C2

C2

1. Structure and Bonding

   • Chemical Bonding
     • Elements react to form compounds by gaining or losing electrons, or by sharing electrons
     • Atoms of metals in group 1 combine with atoms of non-metals in group 7 by transferring electrons to form ions that have the electronic structures of noble gases
   • Ionic Bonding
     • Ionic compounds are held together by strong forces between the oppositely charged ions.
     • the ions from a giant structure or lattice. the strong forces of attraction act throughout the lattice
   • Formulae of ionic compounds
     • the charges on the ions in ionic compounds always cancel each other out
     • the formula of an ionic compound shows the ratio of ions present in the compound
     • sometimes we need brackets to show the ratio of ions in a compound.
   • covalent bonding
     • a covalent bond is formed when two atoms share a pair of electrons
     • the number of covalent bonds depends on the number of electrons it needs to achieve a stable electronic structure.
   • Metals
     • the atoms in metals are closely packed and arranged in regular layers
     • the electrons in the highest energy level are delocalised. the strong electrostatic forces between these electrons and the positively charged metal ions hold the metal together

2. Structure and Properties

   • Giant ionic structures
     • Ionic compounds have high melting points and they are all solids at room temperature
     • Ionic compounds will conduct electricity when we melt them or dissolve them in water. their ions can then move freely and can carry charge through the liquid
   • giant metallic structures
   • simple molecules
   • nanoscience
   • the properties of polymers
   • giant covalent structures

3. How much?

4. Rates and Energy

5. Salts and Electrolysis