S-Cool Revision Summary

S-Cool Revision Summary

Reactivity decreases down the group with increasing atomic number.

Fluorine has the greatest oxidising power of all the halogens. Iodine has the greatest reducing power.

Within a compound, the halogen is most commonly in an oxidation state of -1.

Halogens usually make ionic bonds with metals. However they will form covalent bonds with themselves to form diatomic molecules or with a hydrogen atom.

The hydrogen halides are colourless acidic gases that dissolve in water to form acid solutions.

Thermal stability of the hydrogen halides decreases with increasing atomic number of the halogen.

In aqueous solution, the halogen with the lower atomic number can displace the halide ion with the higher atomic number.

Acidified silver nitrate can be used to distinguish between aqueous halide ions. The silver halides formed can be distinguished by the colour of the precipitate, and by their differing solubilities in aqueous ammonia.