Chapter 5: Chemical formulae and equations

Annotations:

• Simplest whole number ratio. 10g H     80g O Amount of H atoms = mass/ Ar    10/1 = 10 mol Amount of O atoms = 80/16 = 5 mol so ratio 10: 5   2:1  H2O

Annotations:

• They give each other the electron When ionic compounds form + ions attract - ions and arrange into ionic lattice The electrostatic force of attraction between oppositely charged ions  called ionic bond Very strong and need a lot of energy to break and overcome forces. Very high boiling point. 2+ ions have a higher melting point  than + as they attract more strongly.