Occurrence of Oxygen

Read correctly. Mind all signs and figures.

С. Weight

B. Capacity

A. Length

Some Simple Conversions

WEIGHTS and MEASURES

Translate the following sentences. Use a dictionary if necessary.

How to read Decimal and Common Fractions.

The METRIC SYSTEM

Read aloud the text

The fundamental unit of the metric system is the metre. The millimetre and centimetre are the units which the chemist uses very frequently in his work.

If one is to measure extremely short distances, the micron is to be used.

The unit of mass is the gram, milligram or the kilogram.

The unit of the heat measurement is the calorie.

0.1 is read as nought point one (point one);

0.01 - nought point nought one (point nought one);

2.35 - two point three five;

32.305 - three two (thirty two) point three nought five;

½ - a (one) half;!!!

²/₃ - two thirds;!!!

¾ -three quarters (three fourths);

1/1,000,000 - one millionth .!!!

16. Train to read:

0.35 ounce, 0.5%, 49.37 inches, 0.5 km, 1.5kg, +11°C, –218,4°C, 0.25 ton, 2.25 tons, 450 g, 0.03%, 1/100, 1/1,000, 0.6%, +36,6°C.

1. At present there are 1,000 artificial isotopes and about 300 stable ones. 2. One uranium isotope of atomic weight 235 is found in every 140 atoms of the standard weight 238. 3. One of every 5,000 hydrogen atoms has an atomic weight of 2.016 instead of 1.008. 4. A tiny addition of the impurity increase the conductivity 1000,000fold, converting germanium to a conductor. 5. Above 150 kelvin vanadium is a semiconductor, when cooled it becomes a good insulator. 6. Nickel oxide is reduced in resistivity by 13 orders by adding only 1% of helium. 7. Ordinary air contains nearly constant proportions of 3 elementary substances, namely, nitrogen – 75,4%, oxygen – 23.3%, argon – 1.2% by weight. 8. Mercury is stable in the liquid state at about 20°C.

18. It’s interesting to learn some non-metric units of weights and measures.

There are 12 inches in a foot. One inch is 2.5 centimeters. A meter is 39.37 inches.

There are three feet in a yard. There are 5.280 feet in a mile. One mile is 1.6 kilometers.

An average man is about 5 feet, 9 inches tall (5'9"). His average weight is about 150 pounds (lbs). One pound is 450 grams or roughly half a kilogram.

There are 16 ounces in a pound. An ounce is about 28 grams. There are 16 ounces in a pint. A quart is about two pints. There are 2,000 pounds in a ton.

1 kilometer =.62 mile 1 mile = 1.6 km

1 meter = 39.37 inches 1 foot = 3 meter (30 cm)

1 centimeter =.39 inch 1 inch = 2.54 cm

1 liter = about 1 quart 1 ounce = 28 grams

1 kilogram = 2.2 pounds 1 pound = 450 grams

1 gram = 0.35 ounce

D. Temperature Centigrade Fahrenheit

+100°	+212°
0°	+32°
–18°	0°

Water boils at 212°(Fah.) 100°(C).

Water freezes at 32°(Fah.) 0°(C).

Oxygen is the most abundant element in the earth's crust. It constitutes by weight 89% of water, 23% of air (20% by volume), and nearly 50% of the common minerals (silicates).

The nine common elements that compose the solid crust of the earth are the following:

Oxygen - 46.5%	Iron - 5%	Potassium - 2.5%
Silicon - 28%	Sodium - 3%	Magnesium - 2.2%
Aluminium - 8%	Calcium – 3.5%	Titanium - 0.5%

Oxygen is a colorless, odorless gas, which is soluble in wa­ter - one liter of water at 18°C dissolves 35mL (1mL = l milliliter = 1/1000 liter) of oxygen at 1 atm pressure. Oxygen can become a liquid. Its boiling point is –183°C. It can become a solid. Its freezing point is –218,4°C.

20. Translate the text in written form, mind Modals:

The chemical industry needs instruments for accurate measuring. Good measuring instruments are able to give rap­id results. Without modern instrumentation chemical processes were often controlled by a human operator who had to decide what needed to be done. It was rather difficult to do. The results had often to be checked thoroughly.

There are many different kinds of measuring instruments and there is much information about the instruments which are to be used in chemical plants. The purpose of all measuring devices is to control a chemical reaction. In a process controlled by a human operator, the temperature, for example, can be read from a thermometer. The operator is to decide whether the temperature is all right. Then he has to make some measurements. In the automated system, some mechanical or electrical device must replace the human operator to decide whether a process correction is needed and, if so, the extent of the necessary cor­rection.

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