Elements and Compounds, Atoms and Molecules

The world around you is made up of elements and compounds, atoms and molecules. But what are these things?

Atoms

• Atoms are tiny particles which make up elements
• Atoms are particles which cannot be divided further
• There are currently 118 different elements
• Atoms of one element are different to atoms of every other type of element

Molecules

• Are made up of two or more atoms chemically bonded (joined) together
• It is not possible to separate the atoms in a molecule without breaking bonds

Elements

• Elements are made up of just one type of atom
• For example Oxygen, O₂, is a molecule made up of Oxygen atoms only and is therefore an element.
• The periodic table contains all 118 known elements

Compounds

• Compounds are molecules made up of more than one type of atom chemically bonded together.
• For example Water, H₂O, which contains 2 Hydrogen atoms and 1 oxygen atom bonded to each other