Say whether these statements are TRUE or FALSE.

1. Hydrogen produces water when burned. 2. Hydrogen cannot exist as a liquid under any conditions. 3. Engineers and car manufacturers assume the possibility of using hydrogen gas as an efficient and viable car fuel. 4. Hydrogen peroxide is a chemical compound that at certain concentrations can also be used to clean wounds. 5. Zeppelins were reliable and safe. 6. The use of zeppelins was stopped soon after the Hindenburg disaster in 1931. 7. Hydrogen can be potentially dangerous to humans due to fires that can start when it is mixed with air.

2. Match the words to their synonyms:

1) amount	a) to connect
2) to make up	b) enormous
3) mass	c) conversion
4) giant	d) to ruin
5) to bond	e) a chance
6) discovery	f) weight
7) unique	g) to compose
8) transition	h) opening
9) possibility	i) quantity
10) to destroy	j) particular

2. Nitrogen

bulk	об’ємний	a bubble	бульбашка
fluid	рідина	surgery	хірургічна операція
greenhouse gas	парниковий газ	an anesthetic	обезболювальне
decompression sickness	кесонна хвороба	demolition	знищення, руйнування
scuba diving	пірнання з аквалангом	fertilizer	удобрювач, добриво

Nitrogen is a chemical element with the symbol N and atomic number of 7. Under normal conditions nitrogen is a colorless, odorless and tasteless gas. Nitrogen makes up around 78% of the air you breathe; it is present in all living things, including the human body and plants.

Nitrogen gas is used in food storage to keep packaged or bulk foods fresh. It is also used in the making of electronic parts, for industrial purposes and has many other useful applications. Nitrogen gas is often used as an alternative to carbon dioxide for storing beer in pressurized kegs. The smaller bubbles it produces are preferred for some types of beer.

Titan, the largest moon of Saturn, has an atmosphere nearly entirely made of nitrogen (over 98%). It is the only moon in our solar system known to have a dense atmosphere.

Nitrogen is in a liquid state when at a very low temperature. Liquid nitrogen boils at 77 Kelvin (−196°C, −321°F). It is easily transported and has many useful applications including storing items at cold temperatures, in the field of cryogenics (how materials behave at very low temperatures), as a computer coolant (a fluid used to prevent overheating), removing warts and much more.

Decompression sickness (also known as the bends) involves nitrogen bubbles forming in the bloodstream and other important areas of the body when people depressurize too quickly from scuba diving. Similar situations can occur for astronauts and those working in unpressurized aircraft.

Nitrous oxide (also known as laughing gas or by its chemical formula N₂O) is used in hospitals and dental clinics as an anesthetic (removing or reducing pain and general awareness for various surgeries). Nitrous oxide is also used in motor racing to increase the power of engine and speed of the vehicle. When used for this purpose, it is often referred to as nitrous or NOS (Nitrous Oxide System). Nitrous oxide is a considerable greenhouse gas and air pollutant. By weight it has nearly 300 times more impact than carbon dioxide.

Nitroglycerin is a liquid used to create explosives such as dynamite. It is often used in the demolition and construction industries as well as by the military. Nitric acid (HNO₃) is a strong acid often used in the production of fertilizers. Ammonia (NH₃) is another nitrogen compound commonly used in fertilizers.

Дата добавления: 2015-10-30