2015-02-27
844
1. At least three of the remaining four particles are needed to account for the observed relationships. 2. This substance was purified to investigate its properties carefully. 3. Lead is known to be a bright silvery metal with a pronounced bluish colour. 4. The radiation was first thought to consist of gamma-rays, but the energy relationships were found to disagree with this assumption. 5. They proved soluble lead salts to be poisonous. 6. They have been told to examine all the found precipitates. 7. The laboratory appeared to have been equipped very well. 8. The sediment to be investigated appeared on the bottom of the flask. 9. They are likely to have proved this solvent to be very volatile. 10. They were asked to find out all the constituents of the compound. 11. A series of experiments was conducted to determine the effect of adding this element.
3. Заполните пропуски словами, данными ниже. Некоторые слова могут использоваться несколько раз. Переведите предложения.
combustion, rusting, hydrogen, oxygen, nitrogen, argon, inert, reactive, atmosphere, carbon dioxide, cooling, heating, remove, mixture, substance, isolate
1.... is a corrosion of iron or steel to form a hydrate iron (III) oxide.
2.... occurs in the air (78%) and is an essential constituent of proteins and nucleic acids in living organisms.
3.... is a chemical reaction in which a... reacts rapidly with... producing heat and light.
4.... is a colourless, odourless gas, soluble in water, ethanol and acetone.
5.... occurs only in the presence of both water and....
6. Reactions of... are often free-radical chain reactions, which can usually be summarized as the oxidation of carbon to form its oxides and the oxidation of... to form water.
7.... is really prepared in the laboratory by the action of dilute acids on metal carbonates.
8. Though... is essential to all forms of life, the huge amount present in the... is not directly available to most organisms.
9.... is the lightest element and most abundant at the universe.
10.... is an electrochemical process in which different parts of iron surface act as electrodes in a cell reaction.
11. Flame is a luminous... of gases undergoing....
12.... is a by-product (побочный продукт) from the manufacture of lime (известь) and from fermentation process.
