Atoms, elements and compounds

• Chemical symbols represent elements and compounds.
• Word equations and chemical equations represent the changes that happen in chemical reactions.
• All substances are made from tiny particles called atoms.
• An atom is the smallest part of an element that can exist.
• There are over 100 different elements.
• The names and symbols of the elements are shown in the periodic table.
• Elements are arranged into groups with similar properties.
• Groups are numbered from 1 to 7, then 0.
• In the periodic table, metals are on the left , and non-metals are on the right.
• Each box in the periodic table shows the chemical symbol for an element.