a soft, silver-white metal that burns quickly in the air and is used in special hard glasses and fertilizers (= substances that help crops grow better)
potassium
15
a chemical element that is a heavy, silver-coloured metal, liquid at normal temperatures
mercury
15
a chemical element that is a common greyish-coloured metal. It is strong, and exists in very small amounts in blood
iron
15
a chemical element that is a valuable, shiny, yellow metal used to make coins and jewellery
gold
15
a chemical element that is a gas lighter than air, that will not burn and is used in balloons, airships, and some types of lights
helium
15
a chemical element that exists in its pure form as diamond or graphite, and is an important part of other substances such as coal and oil, as well as being contained in all plants and animals
carbon
15
a chemical element that is a reddish-brown metal, used especially for making wire and coins
copper
15
a generally hard and shiny chemical element, such as iron or gold, or a mixture of such elements, such as steel, which usually allows electricity and heat to travel through it
metals
10
a chemical element that is not a metal
non-metal
10
a quality in a substance or material, especially one that means that it can be used in a particular way
property
15
an arrangement of the symbols of chemical elements in rows and columns, showing similarities in chemical behaviour, especially between elements in the same columns
periodic table
15
a simple substance that cannot be reduced to smaller chemical parts
element
15
a chemical element that is the lightest gas, has no colour, taste, or smell, and combines with oxygen to form water
hydrogen
15
a chemical element that is a valuable shiny, white metal, used for making cutlery (= knives, spoons, etc.), jewellery, coins, and decorative objects
silver
15
a chemical element that is a gas with no smell or colour. Its forms a large part of the air on earth, and is needed by animals and plants to live
oxygen
15
a chemical element that is a gas with no smell or colour, does not react with other chemicals, and shines red when an electric current goes through it
