Give the English equivalents for the following words and word combinations.
UNIT VI
HYDROGEN
Section I
Hydrogen is easily the most abundant element in the universe. It is found in the sun and most of the stars, and the planet Jupiter is composed mostly of hydrogen. On Earth, hydrogen is found in the greatest quantities as water. It is present as a gas in the atmosphere only in tiny amounts – less than 1 part per million by volume. Any hydrogen that does enter the atmosphere quickly escapes the Earth ' s gravity into outer space. Most hydrogen is produced by heating natural gas with steam to form syngas (a mixture of hydrogen and carbon monoxide). The syngas is separated to give hydrogen. Hydrogen can also be produced by the electrolysis of water.
WARMING-UP
What forms does hydrogen occur in nature in?
What are the applications of hydrogen nowadays?
Complete the following table on the history of hydrogen discovery using the information given below:
| Year | Discoverer's name | Discovery description |
Names: Robert Boyle, the alchemist Paracelsus, Antoine Lavoisier, Harold Urey and his colleagues at Columbia University, Henry Cavendish.
Years: 1766, 1671, 1931, 1783, the early 1500s.
Descriptions: he detected a second, rarer, form of hydrogen and named it deuterium; he collected the bubbles and showed that they were different from other gases. He later showed that when hydrogen burns it forms water, thereby ending the belief that water was an element; he gave the gas its name hydrogen, meaning water-former; he noted that the bubbles given off when iron filings were added to sulfuric acid were flammable; he made the same observation.
TEXT A
Memorize the meaning of the following words and word combinations.
| apparatus, at the anode, at the cathode, combine with, in combination with, come off, common air, complete, covalent bonds, decompose, decide upon, deuterium, diluted, explode, explosion, half-life, hydride, inflammable, ionize, isotopic form, nuclear, make up a compound, ratio of smth. to smth., release, sole, standard of accuracy, store, tritium, unit of measurement, unit of matter, vitriolic acid, whole number |
Practise your pronunciation.
Mass, ratio, weigh, weighing, weight, whole, measurement, compound, committee, accuracy, diluted vitriolic acid, sulphuric acid, inflammable, covalent bond, alkali, hydrides, cathode, anode, proton, electron, ion.
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3. Make pairs of the words and word combinations in column A and those in column B and make up sentences with them.
| A | B | ||
| 1. | the most important | a) | the atomic weights |
| 2. | make up | b) | air |
| 3. | calculate | c) | a chemical compound |
| 4. | decide upon | d) | hydrides |
| 5. | explode | e) | action of sulphuric acid |
| 6. | inflammable | f) | covalent bonds |
| 7. | the nuclear structure of | g) | with a long noise |
| 8. | form | h) | property of an element |
| 9. | obtain by | i) | ordinary hydrogen |
| 10. | joined with | j) | a standard of accuracy |
Read and translate the text.
HYDROGEN
Hydrogen is the lightest chemical element. Its mass is the unit of measurement for the masses of other elements.
Atomic weight, or mass, was long considered the most important property of an element. By weighing the amounts of individual elements making up a chemical compound and calculating the weight of these ratios to the weight of hydrogen which will combine with the same elements, chemists found that the atomic weights of the other elements are almost, but not quite, whole numbers.
During the nineteenth century a committee of chemists decided upon a standard of accuracy for atomic weights. The committee set the atomic weight of oxygen at 16.000 in order to make the atomic weights of other elements come out closer to whole numbers. That change of standards gave hydrogen the weight of 1.008.
Hydrogen was first obtained in 1766 by Sir Henry Cavendish in London. He found that he could get the gas by dissolving zinc, iron or tin in diluted vitriolic acid (H2SO4). He discovered that a mixture of hydrogen and common air explodes with a long noise, and he was impressed with the lightness of the gas. He named the gas "inflammable air", and A. Lavoisier gave this element the name "hydrogen" (water-former).
Hydrogen exists in three isotopic forms, known as hydrogen (or protium), deuterium and tritium. Tritium is radioactive, with a short half-life. Deuterium is stable, and occurs in a small amount with ordinary hydrogen. Its compound (D2O) is known as heavy water. Slight differences between the properties of ordinary water and heavy water allow their separation, notably by electrolysis, in which ordinary water is decomposed and heavy water becomes concentrated in the water left in the apparatus.
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The nuclear structure of ordinary hydrogen consists of one proton, the unit of matter. This is the same as a hydrogen ion. An electron as the sole planet in this system completes the structure of hydrogen atom.
In combination with oxygen, in the form of water, and with carbon, in the many organic compounds, hydrogen is one of the most abundant elements on the earth. Hydrogen combines with other elements and forms different kinds of compounds, some of which ionize in solution, others which are joined with covalent bonds, yielding organic types of compounds.
Although formerly it used to be classed with the alkali metals or Group I in the periodic table, hydrogen acts as a negative part of the molecule when it is in combination with those metals. It forms hydrides which are in general colourless crystals. Similar compounds are formed with calcium and barium of Group II. The hydrides decompose in water, releasing hydrogen. This property has been used as a convenient way to store hydrogen.
Hydrogen is usually obtained by action of sulphuric acid (H2SO4) on zinc. The metal replaces the hydrogen, which bubbles off a gas. Electrolysis of water also liberates hydrogen at cathode, while oxygen comes off at the anode.
Give the English equivalents for the following words and word combinations.
Cамый лёгкий химический элемент, единица измерения, самое важное свойство, целое число, для того чтобы, получить газ, растворить, разбавленная серная кислота, обычный воздух, лёгкий газ, изотопная форма, радиоактивный, короткий период полураспада, различные химические соединения, незначительные различия, электролиз, состоять из, соединяться с другими элементами, тяжёлая вода, ионизироваться в растворе, щелочные металлы, гидрид, разлагаться в воде, на катоде, на аноде, хранить, единица вещества, завершать структуру, соотношение к весу водорода.
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