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|---|---|---|---|---|
56e06783231d4119001ac0aa | Aspirated_consonant | Icelandic and Faroese have preaspirated [ʰp ʰt ʰk]; some scholars interpret these as consonant clusters as well. In Icelandic, preaspirated stops contrast with bivalent stops and single stops: | What do scholars say the preaspirated [ʰp ʰt ʰk] are too? | {
"text": [
"consonant clusters"
],
"answer_start": [
85
]
} |
56e06783231d4119001ac0ab | Aspirated_consonant | Icelandic and Faroese have preaspirated [ʰp ʰt ʰk]; some scholars interpret these as consonant clusters as well. In Icelandic, preaspirated stops contrast with bivalent stops and single stops: | What do preaspirated stops contrast with in Icelandic? | {
"text": [
"double stops and single stops"
],
"answer_start": [
160
]
} |
56e06851231d4119001ac0b5 | Aspirated_consonant | Preaspirated stops also occur in most Sami languages; for example, in North Sami, the voiceless stop and affricate phonemes /p/, /t/, /ts/, /tʃ/, /k/ are pronounced preaspirated ([ʰp], [ʰt] [ʰts], [ʰtʃ], [ʰk]) when they occur in medial or final position. | The Sami tongue also has what? | {
"text": [
"Preaspirated stops"
],
"answer_start": [
0
]
} |
56e06851231d4119001ac0b6 | Aspirated_consonant | Preaspirated stops also occur in most Sami languages; for example, in North Sami, the voiceless stop and affricate phonemes /p/, /t/, /ts/, /tʃ/, /k/ are pronounced preaspirated ([ʰp], [ʰt] [ʰts], [ʰtʃ], [ʰk]) when they occur in medial or final position. | Which Sami tongue has unvoiced stop and affricate phonemes pronounced preaspirated? | {
"text": [
"North Sami"
],
"answer_start": [
70
]
} |
56e06908231d4119001ac0c4 | Aspirated_consonant | Although most aspirated obstruents in the world's language are stops and affricates, aspirated fricatives such as [sʰ], [fʰ] or [ɕʰ] have been documented in Korean, in a few Tibeto-Burman languages, in some Oto-Manguean languages, and in the Siouan language Ofo. Some languages, such as Choni Tibetan, have up to four contrastive aspirated fricatives [sʰ] [ɕʰ], [ʂʰ] and [xʰ]. | How many contrastive aspirated fricatives does Choni Tibetan have? | {
"text": [
"up to four"
],
"answer_start": [
307
]
} |
56e069f0231d4119001ac0d1 | Aspirated_consonant | True aspirated sonant consonants, as opposed to murmured (breathy-voice) consonants such as the [bʱ], [dʱ], [ɡʱ] that are common in the languages of India, are extremely rare. They have been documented in Kelabit Taa, and the Kx'a languages. Reported aspirated sonant stops, affricates and clicks are [b͡pʰ, d͡tʰ, d͡tsʰ, d͡tʃʰ, ɡ͡kʰ, ɢ͡qʰ, ᶢʘʰ, ᶢǀʰ, ᶢǁʰ, ᶢǃʰ, ᶢǂʰ]. | Indian languages commonly have murmured consonants instead of what? | {
"text": [
"True aspirated voiced consonants"
],
"answer_start": [
0
]
} |
56e069f0231d4119001ac0d2 | Aspirated_consonant | True aspirated sonant consonants, as opposed to murmured (breathy-voice) consonants such as the [bʱ], [dʱ], [ɡʱ] that are common in the languages of India, are extremely rare. They have been documented in Kelabit Taa, and the Kx'a languages. Reported aspirated sonant stops, affricates and clicks are [b͡pʰ, d͡tʰ, d͡tsʰ, d͡tʃʰ, ɡ͡kʰ, ɢ͡qʰ, ᶢʘʰ, ᶢǀʰ, ᶢǁʰ, ᶢǃʰ, ᶢǂʰ]. | True aspirated consonants are considered what? | {
"text": [
"rare"
],
"answer_start": [
170
]
} |
56e069f0231d4119001ac0d3 | Aspirated_consonant | True aspirated sonant consonants, as opposed to murmured (breathy-voice) consonants such as the [bʱ], [dʱ], [ɡʱ] that are common in the languages of India, are extremely rare. They have been documented in Kelabit Taa, and the Kx'a languages. Reported aspirated sonant stops, affricates and clicks are [b͡pʰ, d͡tʰ, d͡tsʰ, d͡tʃʰ, ɡ͡kʰ, ɢ͡qʰ, ᶢʘʰ, ᶢǀʰ, ᶢǁʰ, ᶢǃʰ, ᶢǂʰ]. | True aspirated consonants have been found in Kelabit Taa and what else? | {
"text": [
"Kx'a languages"
],
"answer_start": [
226
]
} |
56e06a517aa994140058e479 | Aspirated_consonant | Aspiration has varying significance in unlike languages. It is either allophonic or phonemic, and may be analyzed as an underlying consonant cluster. | What has a different significance in various languages? | {
"text": [
"Aspiration"
],
"answer_start": [
0
]
} |
56e06a517aa994140058e47a | Aspirated_consonant | Aspiration has varying significance in unlike languages. It is either allophonic or phonemic, and may be analyzed as an underlying consonant cluster. | What two forms can aspiration be in? | {
"text": [
"allophonic or phonemic"
],
"answer_start": [
73
]
} |
56e06ab2231d4119001ac0dd | Aspirated_consonant | In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and unvoiced stops are sometimes aspirated, while voiced stops are usually unaspirated. | Aspiration is what, in English and some other languages? | {
"text": [
"allophonic"
],
"answer_start": [
50
]
} |
56e06ab2231d4119001ac0de | Aspirated_consonant | In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and unvoiced stops are sometimes aspirated, while voiced stops are usually unaspirated. | How are stops distinguished? | {
"text": [
"voicing"
],
"answer_start": [
99
]
} |
56e06ab2231d4119001ac0df | Aspirated_consonant | In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and unvoiced stops are sometimes aspirated, while voiced stops are usually unaspirated. | Voiceless stops are at times what? | {
"text": [
"aspirated"
],
"answer_start": [
142
]
} |
56e06ab2231d4119001ac0e0 | Aspirated_consonant | In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and unvoiced stops are sometimes aspirated, while voiced stops are usually unaspirated. | Voiced stops are most often what? | {
"text": [
"unaspirated"
],
"answer_start": [
184
]
} |
56e06b78231d4119001ac0e5 | Aspirated_consonant | They are unaspirated for almost all speakers when immediately following word-initial s, as in spill, still, skill. After an s elsewhere in a word they are normally unaspirated as well, except sometimes in compound words. When the consonants in a cluster like st are analyzed as belonging to unlike morphemes (heteromorphemic) the stop is aspirated, but when they are analyzed as belonging to one morpheme the stop is unaspirated.[citation needed] For instance, distend has unaspirated [t] since it is not analyzed as two morphemes, but distaste has an aspirated middle [tʰ] because it is analyzed as dis- + taste and the word taste has an aspirated initial t. | When following a word such as spill, they are what for most speakers? | {
"text": [
"unaspirated"
],
"answer_start": [
9
]
} |
56e06b78231d4119001ac0e6 | Aspirated_consonant | They are unaspirated for almost all speakers when immediately following word-initial s, as in spill, still, skill. After an s elsewhere in a word they are normally unaspirated as well, except sometimes in compound words. When the consonants in a cluster like st are analyzed as belonging to unlike morphemes (heteromorphemic) the stop is aspirated, but when they are analyzed as belonging to one morpheme the stop is unaspirated.[citation needed] For instance, distend has unaspirated [t] since it is not analyzed as two morphemes, but distaste has an aspirated middle [tʰ] because it is analyzed as dis- + taste and the word taste has an aspirated initial t. | If the letter s is a different place in the word, it is typical unaspirated unless the word is what? | {
"text": [
"compound words"
],
"answer_start": [
205
]
} |
56e06b78231d4119001ac0e7 | Aspirated_consonant | They are unaspirated for almost all speakers when immediately following word-initial s, as in spill, still, skill. After an s elsewhere in a word they are normally unaspirated as well, except sometimes in compound words. When the consonants in a cluster like st are analyzed as belonging to unlike morphemes (heteromorphemic) the stop is aspirated, but when they are analyzed as belonging to one morpheme the stop is unaspirated.[citation needed] For instance, distend has unaspirated [t] since it is not analyzed as two morphemes, but distaste has an aspirated middle [tʰ] because it is analyzed as dis- + taste and the word taste has an aspirated initial t. | If there is a cluster such as st and it belongs to different morphemes, the stop is what? | {
"text": [
"aspirated"
],
"answer_start": [
11
]
} |
56e06b78231d4119001ac0e8 | Aspirated_consonant | They are unaspirated for almost all speakers when immediately following word-initial s, as in spill, still, skill. After an s elsewhere in a word they are normally unaspirated as well, except sometimes in compound words. When the consonants in a cluster like st are analyzed as belonging to unlike morphemes (heteromorphemic) the stop is aspirated, but when they are analyzed as belonging to one morpheme the stop is unaspirated.[citation needed] For instance, distend has unaspirated [t] since it is not analyzed as two morphemes, but distaste has an aspirated middle [tʰ] because it is analyzed as dis- + taste and the word taste has an aspirated initial t. | If the st belongs to one morpheme, then the stop is what? | {
"text": [
"unaspirated"
],
"answer_start": [
9
]
} |
56e06bd2231d4119001ac0ed | Aspirated_consonant | In many languages, such as Armenian, Korean, Thai, Indo-Aryan languages, Dravidian languages, Icelandic, Ancient Greek, and the varieties of Chinese, tenuis and aspirated consonants are phonemic. Unaspirated consonants like [p˭ s˭] and aspirated consonants like [pʰ ʰp sʰ] are separate phonemes, and words are distinguished by whether they have one or the other. | In languages like Thai and Icelandic, tenuis and aspirated consonants are what? | {
"text": [
"phonemic"
],
"answer_start": [
186
]
} |
56e06bd2231d4119001ac0ee | Aspirated_consonant | In many languages, such as Armenian, Korean, Thai, Indo-Aryan languages, Dravidian languages, Icelandic, Ancient Greek, and the varieties of Chinese, tenuis and aspirated consonants are phonemic. Unaspirated consonants like [p˭ s˭] and aspirated consonants like [pʰ ʰp sʰ] are separate phonemes, and words are distinguished by whether they have one or the other. | [p˭ s˭] and [pʰ ʰp sʰ] are separate what? | {
"text": [
"phonemes"
],
"answer_start": [
286
]
} |
56e06c697aa994140058e493 | Aspirated_consonant | In Danish and most southern varieties of German, the "lenis" consonants transcribed for diachronic reasons as ⟨b d ɡ⟩ are distinguished from their fortis counterparts ⟨p t k⟩, mainly in their lack of aspiration. | How are lenis consonants distinguished from fortis consonants? | {
"text": [
"their lack of aspiration"
],
"answer_start": [
186
]
} |
56e06c697aa994140058e494 | Aspirated_consonant | In Danish and most southern varieties of German, the "lenis" consonants transcribed for diachronic reasons as ⟨b d ɡ⟩ are distinguished from their fortis counterparts ⟨p t k⟩, mainly in their lack of aspiration. | If the lenis are ⟨b d ɡ⟩, what are the fortis counterparts? | {
"text": [
"⟨p t k⟩"
],
"answer_start": [
167
]
} |
56e06cd3231d4119001ac0fd | Aspirated_consonant | Standard Chinese (Mandarin) has stops and affricates distinguished by aspiration: for instance, /t tʰ/, /t͡s t͡sʰ/. In pinyin, tenuis stops are written with letters that represent sonant consonants in English, and aspirated stops with letters that represent voiceless consonants. Thus d represents /t/, and t represents /tʰ/. | Mandarin has stops and affricates that are distinguished by what? | {
"text": [
"aspiration"
],
"answer_start": [
70
]
} |
56e06cd3231d4119001ac0fe | Aspirated_consonant | Standard Chinese (Mandarin) has stops and affricates distinguished by aspiration: for instance, /t tʰ/, /t͡s t͡sʰ/. In pinyin, tenuis stops are written with letters that represent sonant consonants in English, and aspirated stops with letters that represent voiceless consonants. Thus d represents /t/, and t represents /tʰ/. | Tenuis stops have letters that are representative of English voiced consonant in what? | {
"text": [
"pinyin"
],
"answer_start": [
119
]
} |
56e06cd3231d4119001ac0ff | Aspirated_consonant | Standard Chinese (Mandarin) has stops and affricates distinguished by aspiration: for instance, /t tʰ/, /t͡s t͡sʰ/. In pinyin, tenuis stops are written with letters that represent sonant consonants in English, and aspirated stops with letters that represent voiceless consonants. Thus d represents /t/, and t represents /tʰ/. | What kind of stops in pinyin are written with letters that representative of voiceless consonants? | {
"text": [
"aspirated stops"
],
"answer_start": [
214
]
} |
56e06d44231d4119001ac103 | Aspirated_consonant | Wu Chinese has a three-way distinction in stops and affricates: /p pʰ b/. In addition to aspirated and unaspirated consonants, there is a series of muddy consonants, like /b/. These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to exist pronounced with low pitch or light (陽 yáng) tone. | What has a three-way distinction in regards to stops and affricates? | {
"text": [
"Wu Chinese"
],
"answer_start": [
0
]
} |
56e06d44231d4119001ac104 | Aspirated_consonant | Wu Chinese has a three-way distinction in stops and affricates: /p pʰ b/. In addition to aspirated and unaspirated consonants, there is a series of muddy consonants, like /b/. These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to exist pronounced with low pitch or light (陽 yáng) tone. | What is the actual distinction for Wu Chinese? | {
"text": [
"/p pʰ b/"
],
"answer_start": [
64
]
} |
56e06d44231d4119001ac105 | Aspirated_consonant | Wu Chinese has a three-way distinction in stops and affricates: /p pʰ b/. In addition to aspirated and unaspirated consonants, there is a series of muddy consonants, like /b/. These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to exist pronounced with low pitch or light (陽 yáng) tone. | What is /b/ representative of, in addition to aspirated and unaspirated consonants? | {
"text": [
"Muddy consonants"
],
"answer_start": [
259
]
} |
56e06d44231d4119001ac106 | Aspirated_consonant | Wu Chinese has a three-way distinction in stops and affricates: /p pʰ b/. In addition to aspirated and unaspirated consonants, there is a series of muddy consonants, like /b/. These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to exist pronounced with low pitch or light (陽 yáng) tone. | What kind of voice are muddy consonants pronounced with? | {
"text": [
"slack or breathy"
],
"answer_start": [
202
]
} |
56e06dca231d4119001ac10d | Aspirated_consonant | many Indo-Aryan languages have aspirated stops. Sanskrit, Hindi, Bengali, Marathi, and Gujarati have a four-way distinction in stops: voiceless, aspirated, voiced, and breathy-voiced or voiced aspirated, such as /p pʰ b bʱ/. Punjabi has lost breathy-voiced consonants, which resulted in a tone system, and therefore has a distinction between voiceless, aspirated, and voiced: /p pʰ b/. | How many distinctions in stops do languages like Bengali and Hindi have? | {
"text": [
"four"
],
"answer_start": [
103
]
} |
56e06dca231d4119001ac10f | Aspirated_consonant | many Indo-Aryan languages have aspirated stops. Sanskrit, Hindi, Bengali, Marathi, and Gujarati have a four-way distinction in stops: voiceless, aspirated, voiced, and breathy-voiced or voiced aspirated, such as /p pʰ b bʱ/. Punjabi has lost breathy-voiced consonants, which resulted in a tone system, and therefore has a distinction between voiceless, aspirated, and voiced: /p pʰ b/. | What is another term for voice-aspirated? | {
"text": [
"breathy-voiced"
],
"answer_start": [
168
]
} |
56e06dca231d4119001ac111 | Aspirated_consonant | many Indo-Aryan languages have aspirated stops. Sanskrit, Hindi, Bengali, Marathi, and Gujarati have a four-way distinction in stops: voiceless, aspirated, voiced, and breathy-voiced or voiced aspirated, such as /p pʰ b bʱ/. Punjabi has lost breathy-voiced consonants, which resulted in a tone system, and therefore has a distinction between voiceless, aspirated, and voiced: /p pʰ b/. | Which distinction has Punjabi lost? | {
"text": [
"breathy-voiced consonants"
],
"answer_start": [
242
]
} |
56e06eee231d4119001ac117 | Aspirated_consonant | Some of the Dravidian languages, such as Telugu, Tamil, Malayalam, and Kannada, have a distinction between voiced and voiceless, aspirated and unaspirated only in loanwords from Indo-Aryan languages. In native Dravidian words, there is no distinction between these categories and stops are underspecified for voicing and aspiration. | Telegu, Kannada and others are considered to be some of the what languages? | {
"text": [
"Dravidian"
],
"answer_start": [
12
]
} |
56e06eee231d4119001ac119 | Aspirated_consonant | Some of the Dravidian languages, such as Telugu, Tamil, Malayalam, and Kannada, have a distinction between voiced and voiceless, aspirated and unaspirated only in loanwords from Indo-Aryan languages. In native Dravidian words, there is no distinction between these categories and stops are underspecified for voicing and aspiration. | What has no distinction between the categories of voiced, voiceless, aspirated and unaspirated? | {
"text": [
"native Dravidian words"
],
"answer_start": [
203
]
} |
56e070687aa994140058e4c3 | Aspirated_consonant | western Armenian has a two-way distinction between aspirated and voiced: /tʰ d/. western Armenian aspirated /tʰ/ corresponds to Eastern Armenian aspirated /tʰ/ and voiced /d/, and western voiced /d/ corresponds to Eastern voiceless /t/. | What language has two-way distinctions between aspirated and voiced? | {
"text": [
"Western Armenian"
],
"answer_start": [
0
]
} |
56e070687aa994140058e4c4 | Aspirated_consonant | western Armenian has a two-way distinction between aspirated and voiced: /tʰ d/. western Armenian aspirated /tʰ/ corresponds to Eastern Armenian aspirated /tʰ/ and voiced /d/, and western voiced /d/ corresponds to Eastern voiceless /t/. | Western Armenian /tʰ/ compares to eastern Armenian /tʰ/ and what? | {
"text": [
"/d/"
],
"answer_start": [
171
]
} |
56e070687aa994140058e4c5 | Aspirated_consonant | western Armenian has a two-way distinction between aspirated and voiced: /tʰ d/. western Armenian aspirated /tʰ/ corresponds to Eastern Armenian aspirated /tʰ/ and voiced /d/, and western voiced /d/ corresponds to Eastern voiceless /t/. | The Western Armenian voiced /d/ compares to the Eastern Armenian voiceless what? | {
"text": [
"/t/"
],
"answer_start": [
232
]
} |
56e072537aa994140058e4c9 | Aspirated_consonant | Some forms of Grecian before the Koine Grecian period are reconstructed as having aspirated stops. The Classical Attic dialect of Ancient Grecian had a three-way distinction in stops like Eastern Armenian: /t tʰ d/. These stops were called ψιλά, δασέα, μέσα "thin, thick, middle" by Koine Grecian grammarians. | Early Greek (before Koine) have been redone with what? | {
"text": [
"aspirated stops."
],
"answer_start": [
78
]
} |
56e072537aa994140058e4ca | Aspirated_consonant | Some forms of Grecian before the Koine Grecian period are reconstructed as having aspirated stops. The Classical Attic dialect of Ancient Grecian had a three-way distinction in stops like Eastern Armenian: /t tʰ d/. These stops were called ψιλά, δασέα, μέσα "thin, thick, middle" by Koine Grecian grammarians. | What Greek dialect had three-way stop distinction like Eastern Armenian? | {
"text": [
"Classical Attic"
],
"answer_start": [
99
]
} |
56e072537aa994140058e4cc | Aspirated_consonant | Some forms of Grecian before the Koine Grecian period are reconstructed as having aspirated stops. The Classical Attic dialect of Ancient Grecian had a three-way distinction in stops like Eastern Armenian: /t tʰ d/. These stops were called ψιλά, δασέα, μέσα "thin, thick, middle" by Koine Grecian grammarians. | Who referred to the Classical Attic dialect stops by the three distinctions? | {
"text": [
"Greek grammarians"
],
"answer_start": [
283
]
} |
56e072b57aa994140058e4d2 | Aspirated_consonant | There were aspirated stops at three places of articulation: labial, coronal, and velar /pʰ tʰ kʰ/. Earlier Greek, represented by Mycenaean Greek, likely had a labialized velar aspirated stop /kʷʰ/, which later became labial, coronal, or velar depending on dialect and phonic environment. | What is the representation for the three places of articulation? | {
"text": [
"/pʰ tʰ kʰ/"
],
"answer_start": [
87
]
} |
56e072b57aa994140058e4d3 | Aspirated_consonant | There were aspirated stops at three places of articulation: labial, coronal, and velar /pʰ tʰ kʰ/. Earlier Greek, represented by Mycenaean Greek, likely had a labialized velar aspirated stop /kʷʰ/, which later became labial, coronal, or velar depending on dialect and phonic environment. | Earlier Greek was represented by what? | {
"text": [
"Mycenaean Greek"
],
"answer_start": [
129
]
} |
56e072b57aa994140058e4d4 | Aspirated_consonant | There were aspirated stops at three places of articulation: labial, coronal, and velar /pʰ tʰ kʰ/. Earlier Greek, represented by Mycenaean Greek, likely had a labialized velar aspirated stop /kʷʰ/, which later became labial, coronal, or velar depending on dialect and phonic environment. | Whether a stop was labial, coronal or velar depended on what two things? | {
"text": [
"dialect and phonetic environment"
],
"answer_start": [
256
]
} |
56e073267aa994140058e4d9 | Aspirated_consonant | The other Ancient Greek dialects, Ionic, Doric, Aeolic, and Arcadocypriot, likely had the like three-way distinction at one point, but Doric seems to have had a fricative in place of /tʰ/ in the Classical period, and the Ionic and Aeolic dialects sometimes lost aspiration (psilosis). | Dialects such as Aeolic and Doric had how many distinctions that were the same at one point in time? | {
"text": [
"three"
],
"answer_start": [
95
]
} |
56e073267aa994140058e4da | Aspirated_consonant | The other Ancient Greek dialects, Ionic, Doric, Aeolic, and Arcadocypriot, likely had the like three-way distinction at one point, but Doric seems to have had a fricative in place of /tʰ/ in the Classical period, and the Ionic and Aeolic dialects sometimes lost aspiration (psilosis). | Which two dialects lost aspiration at times? | {
"text": [
"Ionic and Aeolic"
],
"answer_start": [
221
]
} |
56e073267aa994140058e4db | Aspirated_consonant | The other Ancient Greek dialects, Ionic, Doric, Aeolic, and Arcadocypriot, likely had the like three-way distinction at one point, but Doric seems to have had a fricative in place of /tʰ/ in the Classical period, and the Ionic and Aeolic dialects sometimes lost aspiration (psilosis). | Rather than /tʰ/, what did the Doric dialect have in place during the Classical period? | {
"text": [
"fricative"
],
"answer_start": [
161
]
} |
56e073d0231d4119001ac177 | Aspirated_consonant | Later, during the Koine Greek period, the aspirated and unvoiced stops /tʰ d/ of Attic Greek lenited to unvoiced and voiced fricatives, yielding /θ ð/ in Medieval and Modern Greek. | Attic Greek lenited to what? | {
"text": [
"voiceless and voiced fricatives"
],
"answer_start": [
105
]
} |
56e073d0231d4119001ac179 | Aspirated_consonant | Later, during the Koine Greek period, the aspirated and unvoiced stops /tʰ d/ of Attic Greek lenited to unvoiced and voiced fricatives, yielding /θ ð/ in Medieval and Modern Greek. | The lenited Attic Greek yielded /θ ð/ in what periods? | {
"text": [
"Medieval and Modern Greek"
],
"answer_start": [
156
]
} |
56e074547aa994140058e4fd | Aspirated_consonant | The term aspiration sometimes refers to the sound change of debuccalization, in which a consonant is lenited (weakened) to go a glottal stop or fricative [ʔ h ɦ]. | Aspiration may refer to a sound change of what? | {
"text": [
"debuccalization"
],
"answer_start": [
60
]
} |
56e074547aa994140058e4fe | Aspirated_consonant | The term aspiration sometimes refers to the sound change of debuccalization, in which a consonant is lenited (weakened) to go a glottal stop or fricative [ʔ h ɦ]. | Debuccalization is when consonants are weakened to become what? | {
"text": [
"glottal stop or fricative"
],
"answer_start": [
132
]
} |
56e074547aa994140058e4ff | Aspirated_consonant | The term aspiration sometimes refers to the sound change of debuccalization, in which a consonant is lenited (weakened) to go a glottal stop or fricative [ʔ h ɦ]. | What is another term for a consonant being weakened? | {
"text": [
"lenited"
],
"answer_start": [
101
]
} |
56e075f87aa994140058e509 | Aspirated_consonant | So-called sonant aspirated consonants are nearly always pronounced instead with breathy voice, a type of phonation or vibration of the vocal folds. The modifier letter ⟨◌ʰ⟩ after a sonant consonant actually represents a breathy-voiced or murmured dental stop, as with the "voiced aspirated" bilabial stop ⟨bʰ⟩ in the Indo-Aryan languages. This consonant is therefore more accurately transcribed as ⟨b̤⟩, with the diacritic for breathy voice, or with the modifier letter ⟨bʱ⟩, a superscript form of the symbol for the sonant glottal fricative ⟨ɦ⟩. | What is breathy voice? | {
"text": [
"a type of phonation or vibration of the vocal folds"
],
"answer_start": [
95
]
} |
56e075f87aa994140058e50d | Aspirated_consonant | So-called sonant aspirated consonants are nearly always pronounced instead with breathy voice, a type of phonation or vibration of the vocal folds. The modifier letter ⟨◌ʰ⟩ after a sonant consonant actually represents a breathy-voiced or murmured dental stop, as with the "voiced aspirated" bilabial stop ⟨bʰ⟩ in the Indo-Aryan languages. This consonant is therefore more accurately transcribed as ⟨b̤⟩, with the diacritic for breathy voice, or with the modifier letter ⟨bʱ⟩, a superscript form of the symbol for the sonant glottal fricative ⟨ɦ⟩. | The ⟨bʰ⟩ in the Indo-Aryan languages is better transcribed how for breathy voice? | {
"text": [
"⟨b̤⟩, with the diacritic"
],
"answer_start": [
398
]
} |
56e0769d7aa994140058e513 | Aspirated_consonant | Some linguists restrict the double-dot subscript ⟨◌̤⟩ to murmured sonorants, such as vowels and nasals, which are murmured throughout their duration, and utilize the superscript hook-aitch ⟨◌ʱ⟩ for the breathy-voiced release of obstruents. | What do some linguists restrict the double-dot subscript ⟨◌̤⟩ to? | {
"text": [
"murmured sonorants"
],
"answer_start": [
57
]
} |
56e0769d7aa994140058e514 | Aspirated_consonant | Some linguists restrict the double-dot subscript ⟨◌̤⟩ to murmured sonorants, such as vowels and nasals, which are murmured throughout their duration, and utilize the superscript hook-aitch ⟨◌ʱ⟩ for the breathy-voiced release of obstruents. | What are, according to the text, murmured for their duration? | {
"text": [
"vowels and nasals"
],
"answer_start": [
85
]
} |
56e0769d7aa994140058e515 | Aspirated_consonant | Some linguists restrict the double-dot subscript ⟨◌̤⟩ to murmured sonorants, such as vowels and nasals, which are murmured throughout their duration, and utilize the superscript hook-aitch ⟨◌ʱ⟩ for the breathy-voiced release of obstruents. | What uses the ⟨◌ʱ⟩? | {
"text": [
"breathy-voiced release of obstruents."
],
"answer_start": [
198
]
} |
56e0711b231d4119001ac141 | Hydrogen | Hydrogen is a chemic element with chemic symbol H and atomic number 1. With an atomic weight of 7000100794000000000♠1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemic substance in the Universe, constituting roughly 75% of all baryonic mass.[note 1] Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1H), has one proton and no neutrons. | What is hydrogens chemical symbol? | {
"text": [
"H"
],
"answer_start": [
0
]
} |
56e0711b231d4119001ac142 | Hydrogen | Hydrogen is a chemic element with chemic symbol H and atomic number 1. With an atomic weight of 7000100794000000000♠1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemic substance in the Universe, constituting roughly 75% of all baryonic mass.[note 1] Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1H), has one proton and no neutrons. | What is the atomic number used for hydrogen? | {
"text": [
"1"
],
"answer_start": [
72
]
} |
56e0711b231d4119001ac143 | Hydrogen | Hydrogen is a chemic element with chemic symbol H and atomic number 1. With an atomic weight of 7000100794000000000♠1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemic substance in the Universe, constituting roughly 75% of all baryonic mass.[note 1] Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1H), has one proton and no neutrons. | What is the atomic weight for hydrogen? | {
"text": [
"7000100794000000000♠1.00794 u"
],
"answer_start": [
100
]
} |
56e0711b231d4119001ac144 | Hydrogen | Hydrogen is a chemic element with chemic symbol H and atomic number 1. With an atomic weight of 7000100794000000000♠1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemic substance in the Universe, constituting roughly 75% of all baryonic mass.[note 1] Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1H), has one proton and no neutrons. | What element is considered the lightest? | {
"text": [
"Hydrogen"
],
"answer_start": [
0
]
} |
56e0733b231d4119001ac16d | Hydrogen | The universal emergence of nuclear hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics. | What form can you find hydrogen is on Earth? | {
"text": [
"molecular"
],
"answer_start": [
239
]
} |
56e0733b231d4119001ac16e | Hydrogen | The universal emergence of nuclear hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics. | What is the molecular make-up of hydrogen? | {
"text": [
"H2"
],
"answer_start": [
257
]
} |
56e0733b231d4119001ac16f | Hydrogen | The universal emergence of nuclear hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics. | What are three properties of hydrogen at normal temperature and normal pressure? | {
"text": [
"colorless, odorless, tasteless"
],
"answer_start": [
142
]
} |
56e0733b231d4119001ac170 | Hydrogen | The universal emergence of nuclear hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics. | What charge does hydrogen display in ionic compounds when it is called a hydride? | {
"text": [
"negative"
],
"answer_start": [
656
]
} |
56e0733b231d4119001ac171 | Hydrogen | The universal emergence of nuclear hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H+. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics. | What field of study has hydrogen and it's properties played a key role in development? | {
"text": [
"quantum mechanics"
],
"answer_start": [
1159
]
} |
56e073a47aa994140058e4df | Hydrogen | Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 1766–81, Henry Cavendish was the first to acknowledge that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-former". | When was hydrogen gas artificially produced for the first time? | {
"text": [
"early 16th century"
],
"answer_start": [
52
]
} |
56e073a47aa994140058e4e1 | Hydrogen | Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 1766–81, Henry Cavendish was the first to acknowledge that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-former". | Who first recognized that hydrogen was a discrete substance? | {
"text": [
"Henry Cavendish"
],
"answer_start": [
121
]
} |
56e073a47aa994140058e4e2 | Hydrogen | Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 1766–81, Henry Cavendish was the first to acknowledge that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-former". | When it is burned what does hydrogen make? | {
"text": [
"water"
],
"answer_start": [
229
]
} |
56e073a47aa994140058e4e3 | Hydrogen | Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 1766–81, Henry Cavendish was the first to acknowledge that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-former". | What is the Greek translation for hydrogen? | {
"text": [
"water-former"
],
"answer_start": [
315
]
} |
56e074137aa994140058e4f5 | Hydrogen | Industrial production is mainly from the steam reforming of natural gas, and less often from more energy-intensive hydrogen production methods like the electrolysis of water. Most hydrogen is employed near its production site, with the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market. Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks. | What market primarily uses ammonia production? | {
"text": [
"the fertilizer market"
],
"answer_start": [
339
]
} |
56e074137aa994140058e4f7 | Hydrogen | Industrial production is mainly from the steam reforming of natural gas, and less often from more energy-intensive hydrogen production methods like the electrolysis of water. Most hydrogen is employed near its production site, with the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market. Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks. | Name a process that uses fossil fuels along with hydrogen. | {
"text": [
"hydrocracking"
],
"answer_start": [
289
]
} |
56e07476231d4119001ac17f | Hydrogen | Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable and will fire in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion for hydrogen is −286 kJ/mol: | For hydrogen what is the enthalpy of combustion? | {
"text": [
"286 kJ/mol"
],
"answer_start": [
202
]
} |
56e07476231d4119001ac180 | Hydrogen | Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable and will fire in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion for hydrogen is −286 kJ/mol: | What are two forms of hydrogen gas? | {
"text": [
"dihydrogen or molecular hydrogen"
],
"answer_start": [
14
]
} |
56e07476231d4119001ac181 | Hydrogen | Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable and will fire in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion for hydrogen is −286 kJ/mol: | Which element has a enthalpy of combustion at −286 kJ/mol? | {
"text": [
"Hydrogen"
],
"answer_start": [
0
]
} |
56e074de231d4119001ac18a | Hydrogen | Hydrogen gas forms explosive mixtures with air if it is 4–74% concentrated and with chlorine if it is 5–95% concentrated. The mixtures may exist ignited by spark, heat or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to the naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine compared to the highly visible plume of a Space Shuttle Solid Rocket Booster. The detection of a burning hydrogen leak may require a flame detector; such leaks can exist very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of the Hindenburg airship was an infamous example of hydrogen combustion; the cause is debated, but the visible orange flames were the result of a rich mixture of hydrogen to oxygen combined with carbon compounds from the airship skin. | What kind of light do hydrogen-oxygen flames make? | {
"text": [
"ultraviolet light"
],
"answer_start": [
318
]
} |
56e074de231d4119001ac18b | Hydrogen | Hydrogen gas forms explosive mixtures with air if it is 4–74% concentrated and with chlorine if it is 5–95% concentrated. The mixtures may exist ignited by spark, heat or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to the naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine compared to the highly visible plume of a Space Shuttle Solid Rocket Booster. The detection of a burning hydrogen leak may require a flame detector; such leaks can exist very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of the Hindenburg airship was an infamous example of hydrogen combustion; the cause is debated, but the visible orange flames were the result of a rich mixture of hydrogen to oxygen combined with carbon compounds from the airship skin. | What caused the Hindenburg to explode? | {
"text": [
"hydrogen combustion"
],
"answer_start": [
801
]
} |
56e0758e7aa994140058e503 | Hydrogen | H2 reacts with every oxidizing element. Hydrogen can respond spontaneously and violently at room temperature with chlorine and fluorine to form the corresponding hydrogen halides, hydrogen chloride and hydrogen fluoride, which are also potentially dangerous acids. | What are two other dangerous acids? | {
"text": [
"hydrogen chloride and hydrogen fluoride"
],
"answer_start": [
178
]
} |
56e0758e7aa994140058e505 | Hydrogen | H2 reacts with every oxidizing element. Hydrogen can respond spontaneously and violently at room temperature with chlorine and fluorine to form the corresponding hydrogen halides, hydrogen chloride and hydrogen fluoride, which are also potentially dangerous acids. | What temperature does hydrogen react with these elements? | {
"text": [
"room temperature"
],
"answer_start": [
90
]
} |
56e077207aa994140058e519 | Hydrogen | The energy levels of hydrogen can exist calculated fairly accurately using the Bohr model of the atom, which conceptualizes the electron as "orbiting" the proton in analogy to the Earth's orbit of the Sun. However, the electromagnetic force attracts electrons and protons to one another, while planets and celestial objects are attracted to each other by gravity. Because of the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. | What model id used to calculate energy levels of hydrogen? | {
"text": [
"Bohr model"
],
"answer_start": [
76
]
} |
56e077207aa994140058e51a | Hydrogen | The energy levels of hydrogen can exist calculated fairly accurately using the Bohr model of the atom, which conceptualizes the electron as "orbiting" the proton in analogy to the Earth's orbit of the Sun. However, the electromagnetic force attracts electrons and protons to one another, while planets and celestial objects are attracted to each other by gravity. Because of the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. | What attracts planets and celestial items? | {
"text": [
"gravity"
],
"answer_start": [
352
]
} |
56e077207aa994140058e51b | Hydrogen | The energy levels of hydrogen can exist calculated fairly accurately using the Bohr model of the atom, which conceptualizes the electron as "orbiting" the proton in analogy to the Earth's orbit of the Sun. However, the electromagnetic force attracts electrons and protons to one another, while planets and celestial objects are attracted to each other by gravity. Because of the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. | What does the electromagnetic force attract to one another? | {
"text": [
"electrons and protons"
],
"answer_start": [
247
]
} |
56e081487aa994140058e588 | Hydrogen | A more accurate description of the hydrogen atom comes from a purely quantum mechanically_skillful treatment that uses the Schrödinger equation, Dirac equation or even the Feynman path integral formulation to calculate the probability density of the electron around the proton. The most complicated treatments allow for the small effects of special relativity and vacuum polarization. In the quantum mechanically_skillful treatment, the electron in a ground state hydrogen atom has no angular momentum at all—an illustration of how the "planetary orbit" conception of electron motion differs from reality. | What kind of movement does the electron not have in ground state? | {
"text": [
"angular"
],
"answer_start": [
463
]
} |
56e087957aa994140058e5c1 | Hydrogen | There exist two unlike spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei. In the orthohydrogen form, the spins of the two protons are parallel and form a triplet state with a molecular spin quantum number of 1 (1⁄2+1⁄2); in the parahydrogen form the spins are antiparallel and form a singlet with a molecular spin quantum number of 0 (1⁄2–1⁄2). At standard temperature and pressure, hydrogen gas contains about 25% of the para form and 75% of the ortho form, also known as the "normal form". The equilibrium ratio of orthohydrogen to parahydrogen depends on temperature, but because the ortho form is an excited state and has a higher energy than the para form, it is unstable and cannot be purified. At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The ortho/para distinction also occurs in other hydrogen-containing molecules or functional groups, such as water and methylene, but is of little significance for their thermal properties. | How many different spin isomers exist? | {
"text": [
"2"
],
"answer_start": [
259
]
} |
56e087957aa994140058e5c2 | Hydrogen | There exist two unlike spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei. In the orthohydrogen form, the spins of the two protons are parallel and form a triplet state with a molecular spin quantum number of 1 (1⁄2+1⁄2); in the parahydrogen form the spins are antiparallel and form a singlet with a molecular spin quantum number of 0 (1⁄2–1⁄2). At standard temperature and pressure, hydrogen gas contains about 25% of the para form and 75% of the ortho form, also known as the "normal form". The equilibrium ratio of orthohydrogen to parahydrogen depends on temperature, but because the ortho form is an excited state and has a higher energy than the para form, it is unstable and cannot be purified. At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The ortho/para distinction also occurs in other hydrogen-containing molecules or functional groups, such as water and methylene, but is of little significance for their thermal properties. | What state are the protons in when in the orthohydrogen form? | {
"text": [
"triplet state"
],
"answer_start": [
200
]
} |
56e087957aa994140058e5c3 | Hydrogen | There exist two unlike spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei. In the orthohydrogen form, the spins of the two protons are parallel and form a triplet state with a molecular spin quantum number of 1 (1⁄2+1⁄2); in the parahydrogen form the spins are antiparallel and form a singlet with a molecular spin quantum number of 0 (1⁄2–1⁄2). At standard temperature and pressure, hydrogen gas contains about 25% of the para form and 75% of the ortho form, also known as the "normal form". The equilibrium ratio of orthohydrogen to parahydrogen depends on temperature, but because the ortho form is an excited state and has a higher energy than the para form, it is unstable and cannot be purified. At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The ortho/para distinction also occurs in other hydrogen-containing molecules or functional groups, such as water and methylene, but is of little significance for their thermal properties. | When hydrogen gas is in standard temperature and pressure, what form is it considered in> | {
"text": [
"normal"
],
"answer_start": [
524
]
} |
56e087957aa994140058e5c4 | Hydrogen | There exist two unlike spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei. In the orthohydrogen form, the spins of the two protons are parallel and form a triplet state with a molecular spin quantum number of 1 (1⁄2+1⁄2); in the parahydrogen form the spins are antiparallel and form a singlet with a molecular spin quantum number of 0 (1⁄2–1⁄2). At standard temperature and pressure, hydrogen gas contains about 25% of the para form and 75% of the ortho form, also known as the "normal form". The equilibrium ratio of orthohydrogen to parahydrogen depends on temperature, but because the ortho form is an excited state and has a higher energy than the para form, it is unstable and cannot be purified. At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The ortho/para distinction also occurs in other hydrogen-containing molecules or functional groups, such as water and methylene, but is of little significance for their thermal properties. | What percent of para form does hydrogen gas contain? | {
"text": [
"25%"
],
"answer_start": [
457
]
} |
56e087957aa994140058e5c5 | Hydrogen | There exist two unlike spin isomers of hydrogen diatomic molecules that differ by the relative spin of their nuclei. In the orthohydrogen form, the spins of the two protons are parallel and form a triplet state with a molecular spin quantum number of 1 (1⁄2+1⁄2); in the parahydrogen form the spins are antiparallel and form a singlet with a molecular spin quantum number of 0 (1⁄2–1⁄2). At standard temperature and pressure, hydrogen gas contains about 25% of the para form and 75% of the ortho form, also known as the "normal form". The equilibrium ratio of orthohydrogen to parahydrogen depends on temperature, but because the ortho form is an excited state and has a higher energy than the para form, it is unstable and cannot be purified. At very low temperatures, the equilibrium state is composed almost exclusively of the para form. The liquid and gas phase thermal properties of pure parahydrogen differ significantly from those of the normal form because of differences in rotational heat capacities, as discussed more fully in spin isomers of hydrogen. The ortho/para distinction also occurs in other hydrogen-containing molecules or functional groups, such as water and methylene, but is of little significance for their thermal properties. | What percent of ortho form does hydrogen gas contain? | {
"text": [
"75%"
],
"answer_start": [
482
]
} |
56e088e17aa994140058e5ce | Hydrogen | The uncatalyzed interconversion between para and ortho H2 increases with increasing temperature; thus rapidly condensed H2 contains big quantities of the high-energy ortho form that converts to the para form very slowly. The ortho/para ratio in condensed H2 is an important consideration in the preparation and storage of liquid hydrogen: the conversion from ortho to para is exothermic and produces enough heat to evaporate some of the hydrogen liquid, leading to loss of liquefied material. Catalysts for the ortho-para interconversion, such as ferric oxide, activated carbon, platinized asbestos, rare earth metals, uranium compounds, chromic oxide, or some nickel compounds, are used during hydrogen cooling. | What are some catalysts used in hydrogen cooling | {
"text": [
"ferric oxide, activated carbon, platinized asbestos, rare earth metals, uranium compounds, chromic oxide, or some nickel compounds"
],
"answer_start": [
549
]
} |
56e08a18231d4119001ac290 | Hydrogen | While H2 is not very reactive under received conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (e.g., F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. When bonded to fluorine, oxygen, or nitrogen, hydrogen can participate in a form of medium-strength noncovalent bonding with other similar molecules between their hydrogens called hydrogen bonding, which is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as the metals and metalloids, in which it takes on a partial negative charge. These compounds are often known as hydrides. | What ind of charge does hydrogen take when mixed with electronegative particles? | {
"text": [
"positive charge"
],
"answer_start": [
270
]
} |
56e08a18231d4119001ac291 | Hydrogen | While H2 is not very reactive under received conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (e.g., F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. When bonded to fluorine, oxygen, or nitrogen, hydrogen can participate in a form of medium-strength noncovalent bonding with other similar molecules between their hydrogens called hydrogen bonding, which is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as the metals and metalloids, in which it takes on a partial negative charge. These compounds are often known as hydrides. | What type of charge does hydrogen take when combined with a metal? | {
"text": [
"negative"
],
"answer_start": [
163
]
} |
56e08a18231d4119001ac292 | Hydrogen | While H2 is not very reactive under received conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (e.g., F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. When bonded to fluorine, oxygen, or nitrogen, hydrogen can participate in a form of medium-strength noncovalent bonding with other similar molecules between their hydrogens called hydrogen bonding, which is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as the metals and metalloids, in which it takes on a partial negative charge. These compounds are often known as hydrides. | When hydrogen forms with a metal, what is the compound called? | {
"text": [
"hydrides"
],
"answer_start": [
734
]
} |
56e08a18231d4119001ac293 | Hydrogen | While H2 is not very reactive under received conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (e.g., F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. When bonded to fluorine, oxygen, or nitrogen, hydrogen can participate in a form of medium-strength noncovalent bonding with other similar molecules between their hydrogens called hydrogen bonding, which is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as the metals and metalloids, in which it takes on a partial negative charge. These compounds are often known as hydrides. | Is H2 reactive in standard conditions? | {
"text": [
"not"
],
"answer_start": [
12
]
} |
56e08b457aa994140058e5e3 | Hydrogen | Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds. The study of their properties is known as organic chemistry and their study in the context of living organisms is known as biochemistry. By some definitions, "organic" compounds are only required to incorporate carbon. However, most of them also incorporate hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways, which seldom involve elementary hydrogen. | What is the form of hydrogen and carbon called? | {
"text": [
"hydrocarbons"
],
"answer_start": [
64
]
} |
56e08b457aa994140058e5e4 | Hydrogen | Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds. The study of their properties is known as organic chemistry and their study in the context of living organisms is known as biochemistry. By some definitions, "organic" compounds are only required to incorporate carbon. However, most of them also incorporate hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways, which seldom involve elementary hydrogen. | What is the form of hydrogen and heteroatoms called? | {
"text": [
"organic compounds"
],
"answer_start": [
194
]
} |
56e08b457aa994140058e5e5 | Hydrogen | Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds. The study of their properties is known as organic chemistry and their study in the context of living organisms is known as biochemistry. By some definitions, "organic" compounds are only required to incorporate carbon. However, most of them also incorporate hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways, which seldom involve elementary hydrogen. | What is the study of organic compounds properties known as? | {
"text": [
"organic chemistry"
],
"answer_start": [
255
]
} |
56e08b457aa994140058e5e6 | Hydrogen | Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds. The study of their properties is known as organic chemistry and their study in the context of living organisms is known as biochemistry. By some definitions, "organic" compounds are only required to incorporate carbon. However, most of them also incorporate hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways, which seldom involve elementary hydrogen. | What is the study of living organisms known as? | {
"text": [
"biochemistry"
],
"answer_start": [
336
]
} |
56e08b457aa994140058e5e7 | Hydrogen | Hydrogen forms a vast array of compounds with carbon called the hydrocarbons, and an even vaster array with heteroatoms that, because of their general association with living things, are called organic compounds. The study of their properties is known as organic chemistry and their study in the context of living organisms is known as biochemistry. By some definitions, "organic" compounds are only required to incorporate carbon. However, most of them also incorporate hydrogen, and because it is the carbon-hydrogen bond which gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated synthetic pathways, which seldom involve elementary hydrogen. | Organic compounds are only required to conatin what? | {
"text": [
"carbon"
],
"answer_start": [
46
]
} |
56e090e27aa994140058e5ee | Hydrogen | Compounds of hydrogen are often called hydrides, a term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a disconfirming or anionic character, denoted H−, and is used when hydrogen forms a compound with a more electropositive element. The existence of the hydride anion, suggested by Gilbert N. Lewis in 1916 for group I and II salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing a stoichiometry quantity of hydrogen at the anode. For hydrides other than group I and II metals, the term is quite misleading, considering the low electronegativity of hydrogen. An exception in group II hydrides is BeH
2, which is polymeric. In lithium aluminium hydride, the AlH−
4 anion carries hydridic centers firmly attached to the Al(III). | Who suggested that hydride anions existed?character does the H atom have in a hydride? | {
"text": [
"Gilbert N. Lewis"
],
"answer_start": [
316
]
} |
56e090e27aa994140058e5f0 | Hydrogen | Compounds of hydrogen are often called hydrides, a term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a disconfirming or anionic character, denoted H−, and is used when hydrogen forms a compound with a more electropositive element. The existence of the hydride anion, suggested by Gilbert N. Lewis in 1916 for group I and II salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing a stoichiometry quantity of hydrogen at the anode. For hydrides other than group I and II metals, the term is quite misleading, considering the low electronegativity of hydrogen. An exception in group II hydrides is BeH
2, which is polymeric. In lithium aluminium hydride, the AlH−
4 anion carries hydridic centers firmly attached to the Al(III). | What group of hydrides is BEH considered polymeric? | {
"text": [
"group II"
],
"answer_start": [
672
]
} |
56e0914c7aa994140058e5f7 | Hydrogen | Although hydrides can exist formed with almost all main-group elements, the number and combination of possible compounds varies widely; for example, there are over 100 binary borane hydrides known, but only one binary aluminium hydride. Binary indium hydride has not yet been identified, although larger complexes exist. | How many binary borane hydrides are known? | {
"text": [
"over 100"
],
"answer_start": [
156
]
} |
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