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a poisonous gas with a strong unpleasant smell, or the gas dissolved in water. It is used in products used for cleaning things.
a gas without colour or smell, produced when you breathe out or when substances containing carbon are burnt. The fact that the earth is getting hotter because of carbon dioxide in the atmosphere is called the greenhouse effect.
chlorofluorocarbon: a gas used in fridges and in some aerosol containers. CFCs are not often used any more because they damage the ozone layer of the Earth’s atmosphere.
a gas used by the police for controlling crowds of people. It hurts your eyes and makes it difficult for you to breathe.
a gas that has no colour and no smell and burns very easily. It is obtained from petroleum and natural gas and is used as a fuel.
a gas obtained from petroleum and natural gas. It is used in making polythene and other chemicals and to make fruit ripen (=become ready to eat or use).
a gas that stops heat from escaping from the atmosphere and causes the greenhouse effect. Carbon dioxide is a greenhouse gas.
informal the gas nitrous oxide used in the past by doctors and dentists to prevent people feeling pain during a medical operation
a gas that is produced when plants in an area of wet land decay and consists mainly of methane
a very poisonous brown gas often found in smog and exhaust from vehicles
a gas used in the past by doctors and dentists to prevent people feeling pain during a medical operation
a gas that does not react with other substances, from the group of gases that includes helium and neon
a mixture of oxygen and a gas called acetylene, used as a fuel for making a very hot flame that cuts metal
science a substance similar to a gas that has almost no electric charge
a hydrocarbon gas obtained from natural gas or petroleum, used as a fuel for cooking and heating
a gas used for forcing a substance out of a spray can when you push the button on top
a poisonous gas used as a weapon by some terrorists
gas produced from shale, used for heating, cooking, etc