Chalk is a fine-textured form of limestone. It is composed of several tiny fragments of the calcite shells or skeletons of ...

Symbol equations are a quick way of representing chemical reactions. They show us what atoms are involved and how they are bonded together. Symbol equations always take the form, reactants → products.

Iron makes up about 5 per cent of the Earth's crust and is the most abundant element in the whole Earth (about 35 per cent). It is the second most abundant metal after aluminium and the fourth most ...