1. BONDING

2. WHY ATOMS COMBINE -1 All atoms want a full outer shell Some atoms will lose electrons to empty their shells These become positively charged ions Metal atoms will lose electrons Positive ions are called CATIONS

3. Why atoms combine - 2 All atoms want a full outer shell Some atoms will gain electrons to fill their shells These become negatively charged ions Non-metal atoms gain electrons Negative ions are called ANIONS

4. IONS Ions have full outer shells Ions have charges Metals make positive ions Positive ions have lost electrons Non-metals form negative ions Negative ions have extra electrons

5. IONIC BONDING When electrons are transferred from one atom to another an ionic bond will form An ionic bond is the attraction between oppositely charged ions Ions are held by strong ELECTROSTATIC FORCES

6. IONIC COMPOUNDS Ionic compounds have very high melting points Ionic compounds dissolve in water (soluble) Ionic compounds cannot conduct electricity when solid because the ions cannot move, they will conduct when molten (melted) or when dissolved in water (aqueous) Ionic salts are made of a metal and a non-metal, eg sodium chloride, magnesium oxide

7. Covalent Bonding All atoms want a full outer shell Some atoms will share electrons to fill their outer shells Sharing electrons makes a covalent bond A molecule is formed when atoms overlap to share electrons Hydrogen gas, H2, oxygen gas, O2 and water are made up molecules