Complete the crossword, then click on "Check" to check your answer. Click on a number in the grid to see the clue or clues for that number. You may need to do some background reading before you are able to complete this. All the best. Dr E.
Substances which burn readily and act as a convenient source of heat.
7.
Fraction of crude oil which is solid at room conditions and liquifies when heated.
9.
See 15 across.
10.
Group name of saturated hydrocarbons.
12.
The commonest Noble Gas in air (at almost 1%).
14.
and 1 across. The gas which is the main cause of acid rain.
15.
and 9 across. Polluting liquid which causes defoliation of trees, freshwater fish to die, damage to stonework of buildings and leaching of nutrients from soil.
16.
Description of the size of soot particles which cause damage to lungs.
19.
Major gas in air which reacts in car engines to give a gas which damages lungs and causes asthma.
22.
Chemical symbol for a noble gas.
23.
and 11 down. Consequence of too much carbon dioxide in the atmosphere.
24.
If petrol vapour and air are mixed, then it is _ _ _ _ _ _ to explode!
25.
See 13 down.
26.
The gas carbon _ _ _ _ _ _ _ _ forms when the oxygen supply to a fuel is limited, and this gas is poisonous.
27.
Naturally occurring liquid fossil fuel.
Down:
1.
See 6 down.
2.
Greek letter with a triangular shape.
3.
Its oxide is water.
5.
Adjective describing the extremely small and meaning 0.000 000 001.
6.
and 1 down. Process used to separate liquids based on their different boiling points.
8.
Weak of hearing.
11.
See 23 across.
13.
and 25 across. Fossil fuel, commonly used in central heating boilers.
17.
Alcohol which can be used as a fuel.
18.
Solid fossil fuel.
20.
Showing excessive desire for food or money.
21.
Description of fuels which have been formed by the slow decomposition of animal or plant remains.