id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 1 25.7k | answers dict |
|---|---|---|---|---|
56e092177aa994140058e5fe | Hydrogen | In inorganic chemistry, hydrides can also serve as bridging ligands that link two metal centers in a coordination complex. This function is particularly common in group 13 elements, especially in boranes (boron hydrides) and aluminium complexes, as well as in clustered carboranes. | What do hydrides that are bridging ligands link up? | {
"text": [
"link two metal centers"
],
"answer_start": [
73
]
} |
56e092177aa994140058e5ff | Hydrogen | In inorganic chemistry, hydrides can also serve as bridging ligands that link two metal centers in a coordination complex. This function is particularly common in group 13 elements, especially in boranes (boron hydrides) and aluminium complexes, as well as in clustered carboranes. | What group is briging ligands most common in? | {
"text": [
"group 13"
],
"answer_start": [
163
]
} |
56e09c507aa994140058e64d | Hydrogen | Oxidation of hydrogen removes its electron and gives H+, which contains no electrons and a nucleus which is usually composed of one proton. That is why H+ is often called a proton. This species is central to discussion of acids. Under the Bronsted-Lowry theory, acids are proton donors, while bases are proton acceptors. | When hydrogen oxidates, what is it removing? | {
"text": [
"electrons"
],
"answer_start": [
75
]
} |
56e09c507aa994140058e64e | Hydrogen | Oxidation of hydrogen removes its electron and gives H+, which contains no electrons and a nucleus which is usually composed of one proton. That is why H+ is often called a proton. This species is central to discussion of acids. Under the Bronsted-Lowry theory, acids are proton donors, while bases are proton acceptors. | When hydrogen oxidates, what does it end up giving? | {
"text": [
"H+"
],
"answer_start": [
53
]
} |
56e09c507aa994140058e651 | Hydrogen | Oxidation of hydrogen removes its electron and gives H+, which contains no electrons and a nucleus which is usually composed of one proton. That is why H+ is often called a proton. This species is central to discussion of acids. Under the Bronsted-Lowry theory, acids are proton donors, while bases are proton acceptors. | What theory suggests that acids are proton donors? | {
"text": [
"Bronsted-Lowry"
],
"answer_start": [
239
]
} |
56e09d01231d4119001ac2d3 | Hydrogen | A bare proton, H+, cannot exist in solution or in ionic crystals, because of its unstoppable attraction to other atoms or molecules with electrons. Except at the high temperatures associated with plasmas, such protons cannot be removed from the electron clouds of atoms and molecules, and will remain attached to them. H... | What is another term for a bare proton? | {
"text": [
"H+"
],
"answer_start": [
15
]
} |
56e0af0c231d4119001ac34d | Hydrogen | To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the "hydronium ion" (H
3O+). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into cl... | Where can oxonium ions be found? | {
"text": [
"in acidic solution with other solvents"
],
"answer_start": [
407
]
} |
56e0af0c231d4119001ac34e | Hydrogen | To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the "hydronium ion" (H
3O+). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into cl... | What other term is a solvated protons referred as? | {
"text": [
"hydronium ion"
],
"answer_start": [
178
]
} |
56e0afa2231d4119001ac354 | Hydrogen | Although exotic on Earth, one of the most common ions in the universe is the H+
3 ion, known as protonated molecular hydrogen or the trihydrogen cation. | What kind of molecular hydrogen is the H+3 knows as? | {
"text": [
"protonated"
],
"answer_start": [
96
]
} |
56e0afa2231d4119001ac355 | Hydrogen | Although exotic on Earth, one of the most common ions in the universe is the H+
3 ion, known as protonated molecular hydrogen or the trihydrogen cation. | What kind of cation is the H+3 knowns as? | {
"text": [
"trihydrogen cation"
],
"answer_start": [
133
]
} |
56e0b0667aa994140058e6a5 | Hydrogen | Hydrogen has three naturally occurring isotopes, denoted 1H, 2H and 3H. Other, highly unstable nuclei (4H to 7H) have been synthesized in the laboratory but not observed in nature. | How many natural isotopes does hydrogen have> | {
"text": [
"3H"
],
"answer_start": [
68
]
} |
56e0b0667aa994140058e6a6 | Hydrogen | Hydrogen has three naturally occurring isotopes, denoted 1H, 2H and 3H. Other, highly unstable nuclei (4H to 7H) have been synthesized in the laboratory but not observed in nature. | What are the names of these isotopes? | {
"text": [
"denoted 1H, 2H and 3H"
],
"answer_start": [
49
]
} |
56e0b0667aa994140058e6a7 | Hydrogen | Hydrogen has three naturally occurring isotopes, denoted 1H, 2H and 3H. Other, highly unstable nuclei (4H to 7H) have been synthesized in the laboratory but not observed in nature. | Which isotopes have unstable nuclei? | {
"text": [
"4H to 7H"
],
"answer_start": [
103
]
} |
56e0b2127aa994140058e6ad | Hydrogen | Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium. The symbols D and T (instead of 2H and 3H) are sometime... | Which element is the only that has different names for its isotopes? | {
"text": [
"Hydrogen"
],
"answer_start": [
0
]
} |
56e0b2127aa994140058e6ae | Hydrogen | Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium. The symbols D and T (instead of 2H and 3H) are sometime... | What are the only two names still used for radioactive isotopes? | {
"text": [
"deuterium and tritium"
],
"answer_start": [
242
]
} |
56e0b2127aa994140058e6af | Hydrogen | Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium. The symbols D and T (instead of 2H and 3H) are sometime... | What are the symbols used for deuterium and tritium? | {
"text": [
"D and T"
],
"answer_start": [
277
]
} |
56e0b2127aa994140058e6b0 | Hydrogen | Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium. The symbols D and T (instead of 2H and 3H) are sometime... | What does the symbol P represent? | {
"text": [
"phosphorus"
],
"answer_start": [
421
]
} |
56e0b2127aa994140058e6b1 | Hydrogen | Hydrogen is the only element that has different names for its isotopes in common use today. During the early study of radioactivity, various heavy radioactive isotopes were given their own names, but such names are no longer used, except for deuterium and tritium. The symbols D and T (instead of 2H and 3H) are sometime... | What are the preferred symbols for deuterium and tritium? | {
"text": [
"2H and 3H"
],
"answer_start": [
297
]
} |
56e16a26e3433e1400422ed6 | Hydrogen | In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "... | What year was the discovery of hydrogen gas? | {
"text": [
"1671"
],
"answer_start": [
3
]
} |
56e16a26e3433e1400422ed7 | Hydrogen | In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "... | Who discovered Hydrogen gas? | {
"text": [
"Robert Boyle"
],
"answer_start": [
9
]
} |
56e16a26e3433e1400422ed8 | Hydrogen | In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "... | Who recognized hydrogen gas as a discreet substance? | {
"text": [
"Henry Cavendish"
],
"answer_start": [
157
]
} |
56e16a26e3433e1400422ed9 | Hydrogen | In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "... | In what year did Henry Cavendish recognize hydrogen gas as a discreet substance? | {
"text": [
"1766"
],
"answer_start": [
151
]
} |
56e16a26e3433e1400422eda | Hydrogen | In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "... | What does gas produce when burned? | {
"text": [
"water"
],
"answer_start": [
457
]
} |
56e16aa1cd28a01900c678c7 | Hydrogen | Lavoisier produced hydrogen for his experiments on mass conservation by reacting a flux of steam with metallic iron through an incandescent iron tube heated in a fire. Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions: | How did Lavoisier produce hydrogen for his experiments? | {
"text": [
"reacting a flux of steam with metallic iron through an incandescent iron tube heated in a fire"
],
"answer_start": [
72
]
} |
56e16b59cd28a01900c678dd | Hydrogen | Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. ... | Who was the first to liquidize hydrogen? | {
"text": [
"James Dewar"
],
"answer_start": [
45
]
} |
56e16b59cd28a01900c678de | Hydrogen | Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. ... | In what year Did James Dewar first liquidize hydrogen? | {
"text": [
"1898"
],
"answer_start": [
60
]
} |
56e16b59cd28a01900c678df | Hydrogen | Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. ... | What year was Deuterium discovered? | {
"text": [
"1931"
],
"answer_start": [
211
]
} |
56e16b59cd28a01900c678e0 | Hydrogen | Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. ... | Who was the first to discover deuterium? | {
"text": [
"Harold Urey"
],
"answer_start": [
219
]
} |
56e16b59cd28a01900c678e1 | Hydrogen | Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. ... | What year was tritium discovered? | {
"text": [
"1934"
],
"answer_start": [
260
]
} |
56e16c1ae3433e1400422efa | Hydrogen | The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen t... | Who invented the hydrogen filled balloons? | {
"text": [
"Jacques Charles"
],
"answer_start": [
50
]
} |
56e16c1ae3433e1400422efb | Hydrogen | The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen t... | What year was hydrogen filled balloons invented? | {
"text": [
"1783"
],
"answer_start": [
69
]
} |
56e16c1ae3433e1400422efd | Hydrogen | The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen t... | what were the hydrogen lifted airships called? | {
"text": [
"Zeppelins"
],
"answer_start": [
342
]
} |
56e16c1ae3433e1400422efe | Hydrogen | The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen t... | In what year did the first zeppelin make flight? | {
"text": [
"1900"
],
"answer_start": [
397
]
} |
56e16ce5cd28a01900c67907 | Hydrogen | The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H2 was used in the Hinde... | Who made the first non stop transatlantic crossing? | {
"text": [
"the British"
],
"answer_start": [
54
]
} |
56e16ce5cd28a01900c67908 | Hydrogen | The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H2 was used in the Hinde... | What year was this done? | {
"text": [
"1919"
],
"answer_start": [
81
]
} |
56e16ce5cd28a01900c6790a | Hydrogen | The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H2 was used in the Hinde... | What year did the airship get destroyed? | {
"text": [
"1937"
],
"answer_start": [
397
]
} |
56e16ce5cd28a01900c6790b | Hydrogen | The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H2 was used in the Hinde... | What city was the ship over when it caught fire? | {
"text": [
"New Jersey"
],
"answer_start": [
377
]
} |
56e170cfcd28a01900c67937 | Hydrogen | In the same year the first hydrogen-cooled turbogenerator went into service with gaseous hydrogen as a coolant in the rotor and the stator in 1937 at Dayton, Ohio, by the Dayton Power & Light Co.; because of the thermal conductivity of hydrogen gas, this is the most common type in its field today. | In what year did the first hydrogen cooled turbogenerator go into service? | {
"text": [
"1937"
],
"answer_start": [
142
]
} |
56e170cfcd28a01900c67939 | Hydrogen | In the same year the first hydrogen-cooled turbogenerator went into service with gaseous hydrogen as a coolant in the rotor and the stator in 1937 at Dayton, Ohio, by the Dayton Power & Light Co.; because of the thermal conductivity of hydrogen gas, this is the most common type in its field today. | What state is the Dayton Power and light Company located? | {
"text": [
"Ohio"
],
"answer_start": [
158
]
} |
56e176a2cd28a01900c6797b | Hydrogen | The nickel hydrogen battery was used for the first time in 1977 aboard the U.S. Navy's Navigation technology satellite-2 (NTS-2). For example, the ISS, Mars Odyssey and the Mars Global Surveyor are equipped with nickel-hydrogen batteries. In the dark part of its orbit, the Hubble Space Telescope is also powered by nick... | What year was the first nickel hydrogen battery used? | {
"text": [
"1977"
],
"answer_start": [
59
]
} |
56e176a2cd28a01900c6797e | Hydrogen | The nickel hydrogen battery was used for the first time in 1977 aboard the U.S. Navy's Navigation technology satellite-2 (NTS-2). For example, the ISS, Mars Odyssey and the Mars Global Surveyor are equipped with nickel-hydrogen batteries. In the dark part of its orbit, the Hubble Space Telescope is also powered by nick... | In what year did the hubble space telescope finally get the nickel hydrogen battery? | {
"text": [
"2009"
],
"answer_start": [
378
]
} |
56e17de1e3433e1400422f78 | Hydrogen | Because of its simple atomic structure, consisting only of a proton and an electron, the hydrogen atom, together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. Furthermore, the corresponding simplicity of the hydrogen molecule and th... | What is the hydrogen atom made up of? | {
"text": [
"a proton and an electron"
],
"answer_start": [
59
]
} |
56e17de1e3433e1400422f79 | Hydrogen | Because of its simple atomic structure, consisting only of a proton and an electron, the hydrogen atom, together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. Furthermore, the corresponding simplicity of the hydrogen molecule and th... | What theory is the hydrogen atom a big part of? | {
"text": [
"atomic structure"
],
"answer_start": [
22
]
} |
56e17de1e3433e1400422f7a | Hydrogen | Because of its simple atomic structure, consisting only of a proton and an electron, the hydrogen atom, together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. Furthermore, the corresponding simplicity of the hydrogen molecule and th... | When was the quantum mechanical treatment of the hydrogen atom developed? | {
"text": [
"1920s"
],
"answer_start": [
526
]
} |
56e17f00e3433e1400422f86 | Hydrogen | One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H2 unaccountably departs from that of a diatomic gas below room tempe... | Who observed the specific heat capacity of H2? | {
"text": [
"Maxwell"
],
"answer_start": [
97
]
} |
56e17f00e3433e1400422f87 | Hydrogen | One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H2 unaccountably departs from that of a diatomic gas below room tempe... | What cause H2 to resemble monatomic gas? | {
"text": [
"spacing of the (quantized) rotational energy levels"
],
"answer_start": [
473
]
} |
56e17f00e3433e1400422f88 | Hydrogen | One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H2 unaccountably departs from that of a diatomic gas below room tempe... | What theory supports this? | {
"text": [
"quantum theory"
],
"answer_start": [
427
]
} |
56e1934be3433e1400422fd2 | Hydrogen | Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms (most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as d... | What percent of normal matter is hydrogen? | {
"text": [
"75%"
],
"answer_start": [
88
]
} |
56e1934be3433e1400422fd3 | Hydrogen | Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms (most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as d... | What percent of atoms is hydrogen? | {
"text": [
"90%"
],
"answer_start": [
126
]
} |
56e1934be3433e1400422fd4 | Hydrogen | Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms (most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as d... | What 2 forms of mass is most of the universe consisted of? | {
"text": [
"dark matter and dark energy"
],
"answer_start": [
319
]
} |
56e1934be3433e1400422fd6 | Hydrogen | Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms (most of the mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as d... | Clouds of H2 form what? | {
"text": [
"stars"
],
"answer_start": [
393
]
} |
56e1944ae3433e1400422fdc | Hydrogen | Throughout the universe, hydrogen is mostly found in the atomic and plasma states whose properties are quite different from molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from the Sun and oth... | In what states is hydrogen mostly found in the universe? | {
"text": [
"atomic and plasma"
],
"answer_start": [
57
]
} |
56e1944ae3433e1400422fdd | Hydrogen | Throughout the universe, hydrogen is mostly found in the atomic and plasma states whose properties are quite different from molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from the Sun and oth... | Hydrogens electron and proton are not bound together in what state? | {
"text": [
"plasma"
],
"answer_start": [
68
]
} |
56e1944ae3433e1400422fdf | Hydrogen | Throughout the universe, hydrogen is mostly found in the atomic and plasma states whose properties are quite different from molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from the Sun and oth... | in the interstellar medium, what state is hydrogen in? | {
"text": [
"neutral atomic state"
],
"answer_start": [
559
]
} |
56e1944ae3433e1400422fe0 | Hydrogen | Throughout the universe, hydrogen is mostly found in the atomic and plasma states whose properties are quite different from molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from the Sun and oth... | The neutral hydrogen found in the damped Lyman-alpha systems dominates what? | {
"text": [
"cosmological baryonic density of the Universe"
],
"answer_start": [
712
]
} |
56e1954fcd28a01900c679dd | Hydrogen | Under ordinary conditions on Earth, elemental hydrogen exists as the diatomic gas, H2. However, hydrogen gas is very rare in the Earth's atmosphere (1 ppm by volume) because of its light weight, which enables it to escape from Earth's gravity more easily than heavier gases. However, hydrogen is the third most abundant ... | How abundant is hydrogen on the earths surface? | {
"text": [
"third most abundant"
],
"answer_start": [
300
]
} |
56e1954fcd28a01900c679df | Hydrogen | Under ordinary conditions on Earth, elemental hydrogen exists as the diatomic gas, H2. However, hydrogen gas is very rare in the Earth's atmosphere (1 ppm by volume) because of its light weight, which enables it to escape from Earth's gravity more easily than heavier gases. However, hydrogen is the third most abundant ... | what produces hydrogen gas? | {
"text": [
"bacteria and algae"
],
"answer_start": [
458
]
} |
56e1963acd28a01900c679e5 | Hydrogen | A molecular form called protonated molecular hydrogen (H+
3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen from cosmic rays. This charged ion has also been observed in the upper atmosphere of the planet Jupiter. The ion is relatively stable in the environment of outer sp... | What molecular form is found in the interstellar medium? | {
"text": [
"protonated molecular hydrogen"
],
"answer_start": [
24
]
} |
56e1963acd28a01900c679e7 | Hydrogen | A molecular form called protonated molecular hydrogen (H+
3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen from cosmic rays. This charged ion has also been observed in the upper atmosphere of the planet Jupiter. The ion is relatively stable in the environment of outer sp... | What generates protonated molecular hydrogen? | {
"text": [
"ionization of molecular hydrogen from cosmic rays"
],
"answer_start": [
123
]
} |
56e1963acd28a01900c679e8 | Hydrogen | A molecular form called protonated molecular hydrogen (H+
3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen from cosmic rays. This charged ion has also been observed in the upper atmosphere of the planet Jupiter. The ion is relatively stable in the environment of outer sp... | On what planet can you find protonated molecular hydrogen? | {
"text": [
"Jupiter"
],
"answer_start": [
252
]
} |
56e1963acd28a01900c679e9 | Hydrogen | A molecular form called protonated molecular hydrogen (H+
3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen from cosmic rays. This charged ion has also been observed in the upper atmosphere of the planet Jupiter. The ion is relatively stable in the environment of outer sp... | In what way can Neutral triatomic hydrogen exist? | {
"text": [
"excited form"
],
"answer_start": [
543
]
} |
56e196cfcd28a01900c679f0 | Hydrogen | H
2 is produced in chemistry and biology laboratories, often as a by-product of other reactions; in industry for the hydrogenation of unsaturated substrates; and in nature as a means of expelling reducing equivalents in biochemical reactions. | How does nature produce H2? | {
"text": [
"expelling reducing equivalents in biochemical reactions"
],
"answer_start": [
186
]
} |
56e196cfcd28a01900c679f1 | Hydrogen | H
2 is produced in chemistry and biology laboratories, often as a by-product of other reactions; in industry for the hydrogenation of unsaturated substrates; and in nature as a means of expelling reducing equivalents in biochemical reactions. | How do labs produce H2? | {
"text": [
"by-product of other reactions"
],
"answer_start": [
66
]
} |
56e197a3cd28a01900c67a00 | Hydrogen | The electrolysis of water is a simple method of producing hydrogen. A low voltage current is run through the water, and gaseous oxygen forms at the anode while gaseous hydrogen forms at the cathode. Typically the cathode is made from platinum or another inert metal when producing hydrogen for storage. If, however, the ... | What is an easy way to produce hydrogen? | {
"text": [
"electrolysis of water"
],
"answer_start": [
4
]
} |
56e197a3cd28a01900c67a02 | Hydrogen | The electrolysis of water is a simple method of producing hydrogen. A low voltage current is run through the water, and gaseous oxygen forms at the anode while gaseous hydrogen forms at the cathode. Typically the cathode is made from platinum or another inert metal when producing hydrogen for storage. If, however, the ... | Where does the gaseous oxygen form at? | {
"text": [
"anode"
],
"answer_start": [
148
]
} |
56e197a3cd28a01900c67a03 | Hydrogen | The electrolysis of water is a simple method of producing hydrogen. A low voltage current is run through the water, and gaseous oxygen forms at the anode while gaseous hydrogen forms at the cathode. Typically the cathode is made from platinum or another inert metal when producing hydrogen for storage. If, however, the ... | Where does the gaseous hydrogen form at? | {
"text": [
"cathode"
],
"answer_start": [
190
]
} |
56e19878cd28a01900c67a14 | Hydrogen | An alloy of aluminium and gallium in pellet form added to water can be used to generate hydrogen. The process also produces alumina, but the expensive gallium, which prevents the formation of an oxide skin on the pellets, can be re-used. This has important potential implications for a hydrogen economy, as hydrogen can ... | When you combine an alloy of alluminum and gallium to water, what do you get? | {
"text": [
"hydrogen"
],
"answer_start": [
88
]
} |
56e19878cd28a01900c67a15 | Hydrogen | An alloy of aluminium and gallium in pellet form added to water can be used to generate hydrogen. The process also produces alumina, but the expensive gallium, which prevents the formation of an oxide skin on the pellets, can be re-used. This has important potential implications for a hydrogen economy, as hydrogen can ... | What else can it produce? | {
"text": [
"alumina"
],
"answer_start": [
124
]
} |
56e19878cd28a01900c67a16 | Hydrogen | An alloy of aluminium and gallium in pellet form added to water can be used to generate hydrogen. The process also produces alumina, but the expensive gallium, which prevents the formation of an oxide skin on the pellets, can be re-used. This has important potential implications for a hydrogen economy, as hydrogen can ... | What can be reused after the formation? | {
"text": [
"the expensive gallium"
],
"answer_start": [
137
]
} |
56e1993fcd28a01900c67a1c | Hydrogen | Hydrogen can be prepared in several different ways, but economically the most important processes involve removal of hydrogen from hydrocarbons. Commercial bulk hydrogen is usually produced by the steam reforming of natural gas. At high temperatures (1000–1400 K, 700–1100 °C or 1300–2000 °F), steam (water vapor) reacts... | The most economical way to prepare hydrogen involves removing it from what? | {
"text": [
"hydrocarbons"
],
"answer_start": [
131
]
} |
56e1993fcd28a01900c67a1e | Hydrogen | Hydrogen can be prepared in several different ways, but economically the most important processes involve removal of hydrogen from hydrocarbons. Commercial bulk hydrogen is usually produced by the steam reforming of natural gas. At high temperatures (1000–1400 K, 700–1100 °C or 1300–2000 °F), steam (water vapor) reacts... | What temperature is needed for steam to react with methane? | {
"text": [
"1000–1400 K, 700–1100 °C or 1300–2000 °F"
],
"answer_start": [
251
]
} |
56e19ab0e3433e1400423000 | Hydrogen | This reaction is favored at low pressures but is nonetheless conducted at high pressures (2.0 MPa, 20 atm or 600 inHg). This is because high-pressure H
2 is the most marketable product and Pressure Swing Adsorption (PSA) purification systems work better at higher pressures. The product mixture is known as "synthesis g... | At what pressure does PSA work best in? | {
"text": [
"high pressures"
],
"answer_start": [
74
]
} |
56e19ab0e3433e1400423001 | Hydrogen | This reaction is favored at low pressures but is nonetheless conducted at high pressures (2.0 MPa, 20 atm or 600 inHg). This is because high-pressure H
2 is the most marketable product and Pressure Swing Adsorption (PSA) purification systems work better at higher pressures. The product mixture is known as "synthesis g... | What is synthesis gas used for? | {
"text": [
"production of methanol"
],
"answer_start": [
366
]
} |
56e19ab0e3433e1400423002 | Hydrogen | This reaction is favored at low pressures but is nonetheless conducted at high pressures (2.0 MPa, 20 atm or 600 inHg). This is because high-pressure H
2 is the most marketable product and Pressure Swing Adsorption (PSA) purification systems work better at higher pressures. The product mixture is known as "synthesis g... | Besides methane, what else can be used to produce synthesis gas? | {
"text": [
"Hydrocarbons"
],
"answer_start": [
412
]
} |
56e19b21e3433e140042300a | Hydrogen | Consequently, steam reforming typically employs an excess of H
2O. Additional hydrogen can be recovered from the steam by use of carbon monoxide through the water gas shift reaction, especially with an iron oxide catalyst. This reaction is also a common industrial source of carbon dioxide: | How can it be recovered through steam? | {
"text": [
"use of carbon monoxide through the water gas shift reaction"
],
"answer_start": [
122
]
} |
56e19ba6e3433e1400423011 | Hydrogen | Hydrogen is sometimes produced and consumed in the same industrial process, without being separated. In the Haber process for the production of ammonia, hydrogen is generated from natural gas. Electrolysis of brine to yield chlorine also produces hydrogen as a co-product. | When hydrogen is generated from natural gas, what des it produce? | {
"text": [
"ammonia"
],
"answer_start": [
144
]
} |
56e19ba6e3433e1400423012 | Hydrogen | Hydrogen is sometimes produced and consumed in the same industrial process, without being separated. In the Haber process for the production of ammonia, hydrogen is generated from natural gas. Electrolysis of brine to yield chlorine also produces hydrogen as a co-product. | How is hydrogen produced as a co product? | {
"text": [
"Electrolysis of brine to yield chlorine"
],
"answer_start": [
193
]
} |
56e19c6ee3433e1400423021 | Hydrogen | There are more than 200 thermochemical cycles which can be used for water splitting, around a dozen of these cycles such as the iron oxide cycle, cerium(IV) oxide–cerium(III) oxide cycle, zinc zinc-oxide cycle, sulfur-iodine cycle, copper-chlorine cycle and hybrid sulfur cycle are under research and in testing phase to... | What are the thermochemical cycyles in a testing phase for? | {
"text": [
"produce hydrogen and oxygen from water and heat without using electricity"
],
"answer_start": [
321
]
} |
56e19c6ee3433e1400423022 | Hydrogen | There are more than 200 thermochemical cycles which can be used for water splitting, around a dozen of these cycles such as the iron oxide cycle, cerium(IV) oxide–cerium(III) oxide cycle, zinc zinc-oxide cycle, sulfur-iodine cycle, copper-chlorine cycle and hybrid sulfur cycle are under research and in testing phase to... | What are labs trying to produce hydrogen from? | {
"text": [
"solar energy and water"
],
"answer_start": [
543
]
} |
56e19c6ee3433e1400423023 | Hydrogen | There are more than 200 thermochemical cycles which can be used for water splitting, around a dozen of these cycles such as the iron oxide cycle, cerium(IV) oxide–cerium(III) oxide cycle, zinc zinc-oxide cycle, sulfur-iodine cycle, copper-chlorine cycle and hybrid sulfur cycle are under research and in testing phase to... | What countries are testing this? | {
"text": [
"France, Germany, Greece, Japan, and the USA"
],
"answer_start": [
435
]
} |
56e19cebe3433e1400423028 | Hydrogen | Under anaerobic conditions, iron and steel alloys are slowly oxidized by the protons of water concomitantly reduced in molecular hydrogen (H
2). The anaerobic corrosion of iron leads first to the formation of ferrous hydroxide (green rust) and can be described by the following reaction: | What condition is iron and steel alloys slowly oxidized? | {
"text": [
"anaerobic"
],
"answer_start": [
6
]
} |
56e19cebe3433e1400423029 | Hydrogen | Under anaerobic conditions, iron and steel alloys are slowly oxidized by the protons of water concomitantly reduced in molecular hydrogen (H
2). The anaerobic corrosion of iron leads first to the formation of ferrous hydroxide (green rust) and can be described by the following reaction: | What does the anaerobic corrosion of iron lead to? | {
"text": [
"formation of ferrous hydroxide"
],
"answer_start": [
196
]
} |
56e19cebe3433e140042302a | Hydrogen | Under anaerobic conditions, iron and steel alloys are slowly oxidized by the protons of water concomitantly reduced in molecular hydrogen (H
2). The anaerobic corrosion of iron leads first to the formation of ferrous hydroxide (green rust) and can be described by the following reaction: | What is another name for formation of ferrous hydroxide? | {
"text": [
"green rust"
],
"answer_start": [
228
]
} |
56e19d84e3433e140042302e | Hydrogen | In its turn, under anaerobic conditions, the ferrous hydroxide (Fe(OH)
2 ) can be oxidized by the protons of water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction: | Under what condition can ferrous hydroxide be oxidized? | {
"text": [
"anaerobic"
],
"answer_start": [
19
]
} |
56e19d84e3433e140042302f | Hydrogen | In its turn, under anaerobic conditions, the ferrous hydroxide (Fe(OH)
2 ) can be oxidized by the protons of water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction: | What does this process form? | {
"text": [
"magnetite and molecular hydrogen"
],
"answer_start": [
123
]
} |
56e19d84e3433e1400423030 | Hydrogen | In its turn, under anaerobic conditions, the ferrous hydroxide (Fe(OH)
2 ) can be oxidized by the protons of water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction: | What reaction describes this process? | {
"text": [
"Schikorr reaction"
],
"answer_start": [
190
]
} |
56e19e9ccd28a01900c67a22 | Hydrogen | In the absence of atmospheric oxygen (O
2), in deep geological conditions prevailing far away from Earth atmosphere, hydrogen (H
2) is produced during the process of serpentinization by the anaerobic oxidation by the water protons (H+) of the ferrous (Fe2+) silicate present in the crystal lattice of the fayalite (Fe
2S... | How is hydrogen produced when there is no atmospheric oxygen? | {
"text": [
"serpentinization by the anaerobic oxidation"
],
"answer_start": [
166
]
} |
56e19e9ccd28a01900c67a23 | Hydrogen | In the absence of atmospheric oxygen (O
2), in deep geological conditions prevailing far away from Earth atmosphere, hydrogen (H
2) is produced during the process of serpentinization by the anaerobic oxidation by the water protons (H+) of the ferrous (Fe2+) silicate present in the crystal lattice of the fayalite (Fe
2S... | Where do you find silicate? | {
"text": [
"crystal lattice of the fayalite"
],
"answer_start": [
282
]
} |
56e19edbe3433e140042303e | Hydrogen | From all the fault gases formed in power transformers, hydrogen is the most common and is generated under most fault conditions; thus, formation of hydrogen is an early indication of serious problems in the transformer's life cycle. | What is the most common gas found in power tranformers? | {
"text": [
"hydrogen"
],
"answer_start": [
55
]
} |
56e19fb6cd28a01900c67a26 | Hydrogen | Large quantities of H
2 are needed in the petroleum and chemical industries. The largest application of H
2 is for the processing ("upgrading") of fossil fuels, and in the production of ammonia. The key consumers of H
2 in the petrochemical plant include hydrodealkylation, hydrodesulfurization, and hydrocracking. H
2 h... | Where are large quantities of H2 needed? | {
"text": [
"petroleum and chemical industries"
],
"answer_start": [
42
]
} |
56e19fb6cd28a01900c67a28 | Hydrogen | Large quantities of H
2 are needed in the petroleum and chemical industries. The largest application of H
2 is for the processing ("upgrading") of fossil fuels, and in the production of ammonia. The key consumers of H
2 in the petrochemical plant include hydrodealkylation, hydrodesulfurization, and hydrocracking. H
2 h... | What are the consumers of H2 in petrochemical plant? | {
"text": [
"hydrodealkylation, hydrodesulfurization, and hydrocracking"
],
"answer_start": [
255
]
} |
56e1a1e1cd28a01900c67a36 | Hydrogen | Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladiu... | Where is hydrogen highly soluble? | {
"text": [
"rare earth and transition metals"
],
"answer_start": [
35
]
} |
56e1a1e1cd28a01900c67a37 | Hydrogen | Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladiu... | Where can you find soluble hydrogen? | {
"text": [
"nanocrystalline and amorphous metals"
],
"answer_start": [
91
]
} |
56e1a1e1cd28a01900c67a38 | Hydrogen | Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladiu... | What influences hydrogens solubility in metals? | {
"text": [
"local distortions or impurities in the crystal lattice"
],
"answer_start": [
176
]
} |
56e1a1e1cd28a01900c67a39 | Hydrogen | Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladiu... | When are these useful? | {
"text": [
"when hydrogen is purified by passage through hot palladium disks"
],
"answer_start": [
263
]
} |
56e1a1e1cd28a01900c67a3a | Hydrogen | Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladiu... | When is it damaging? | {
"text": [
"gas's high solubility is a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks"
],
"answer_start": [
337
]
} |
56e1a28ee3433e140042304c | Hydrogen | Apart from its use as a reactant, H
2 has wide applications in physics and engineering. It is used as a shielding gas in welding methods such as atomic hydrogen welding. H2 is used as the rotor coolant in electrical generators at power stations, because it has the highest thermal conductivity of any gas. Liquid H2 is u... | Where else is H2 applied? | {
"text": [
"in physics and engineering"
],
"answer_start": [
60
]
} |
56e1a28ee3433e140042304e | Hydrogen | Apart from its use as a reactant, H
2 has wide applications in physics and engineering. It is used as a shielding gas in welding methods such as atomic hydrogen welding. H2 is used as the rotor coolant in electrical generators at power stations, because it has the highest thermal conductivity of any gas. Liquid H2 is u... | How is H2 used in electrical generators at power stations? | {
"text": [
"as the rotor coolant"
],
"answer_start": [
181
]
} |
56e1a28ee3433e140042304f | Hydrogen | Apart from its use as a reactant, H
2 has wide applications in physics and engineering. It is used as a shielding gas in welding methods such as atomic hydrogen welding. H2 is used as the rotor coolant in electrical generators at power stations, because it has the highest thermal conductivity of any gas. Liquid H2 is u... | Why is it used as the rotor coolant? | {
"text": [
"it has the highest thermal conductivity of any gas"
],
"answer_start": [
254
]
} |
56e1a28ee3433e1400423050 | Hydrogen | Apart from its use as a reactant, H
2 has wide applications in physics and engineering. It is used as a shielding gas in welding methods such as atomic hydrogen welding. H2 is used as the rotor coolant in electrical generators at power stations, because it has the highest thermal conductivity of any gas. Liquid H2 is u... | What research uses liquid H2? | {
"text": [
"cryogenic"
],
"answer_start": [
327
]
} |
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