11. Open the brackets choosing the suitable word. Translate the sentences into Russian:

1. (A balance, a calorimeter, a thermometer) is a device which determines the quantity, but not the quality of heat in a body. 2. If a chemist determines mass, he is to employ (a flask, a thermometer, a balance). 3. (A calorimeter, a flask, a microscope) is used if a chemist must examine small samples of matter. 4. For the measurement of volumes of gases a chem­ist uses (burettes, pipettes, gas burettes). 5. The unit of (volume, mass) in the metric system is the gram. 6. On (the Centigrade scale, the Fahrenheit scale) the freezing point of water is 0°. 7. If a chemist must measure extremely short distances, (the centimetre, the micron) is to be used.

12. Explain what are the following tools and devices used for:

spectrometer, spectrograph, viscometer, polarimeter, barometer, hydrometer, calorimeter, colorimeter, diameter, elastometer, electrometer, galvanometer, manometer, manograph, tautomer, voltmeter, volumeter.

13. Read these words and word-combinations correctly:

liter, milliliter, meter, millimeter, gram, milligram, cubic, cubic centimeter, micron, ounce, pint, pound, inch, yard, per cent, 20 per cent by volume, degree, four degrees Centigrade, 32 degrees Fahrenheit.

14. Read aloud the text

The metric system

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.

15. How to read Decimal and Common Fractions.

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.

17. Translate the following sentences. Use a dictionary if necessary.

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.