When elements react, their atoms join with other atoms to form compounds. This involves giving, taking or sharing __________ and the atoms are held together by chemical __________.
We can write down a reaction in two forms, a word equation or a chemical symbol equation. The chemicals that are put into the reaction are called reactants, and those that are made are called products. They are separated by an arrow which is read as 'goes to'
Reactants → Products
No atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants. This is known as 'Conservation of Mass'. This is often forgotten when one of the reactants or products is a gas, as it can not be weighted.