Chemistry

• Elements = same number of electrons = react in a similiar way
• Mendeleev arranged elements - increasing atomic mass. Elements in the same period - same properties = similar electronic stucture.

• Bonding

Positive and negative ions ->held by electrostaic attraction

• Metals - positive ions - called cations
• Non - metals = negative ions -> anions

Negative ion -> ends in -ide,       Negative ion containing oxygen -> ends in -ate

       e. g pottasium bromide                         e.g. Magnesium carbonate