Period 3 Elements

All trends listed here are for progression from left to right of the periodic table.

Reactions with water Na and Mg, Reactivity decreases

The elements progress from metals to non-metals.

Period 3 oxides

- The amount of oxygen per mole of the element increases.

- The oxides go from ionic to covalent in nature

- The oxides go from basic to acidic

- Boiling points start high because of the strong ionic forces but become higher in the middle oxides have mixed ionic covalent nature but still form giant lattices so have high boiling points. The latter few elements form simple molecules and so have relatively low boiling points.

- With water the metal oxides form alkalis, aluminium and silicon oxide are insoluble, the non metal oxides form acidic solutions

Period 3 chlorides

- The amount of chlorine atoms per mole of the elements increases across the period.

- Sodium and magnesium chloride are ionic where as aluminium chloride is covalent as are the chlorides of the other elements.

- The boiling points decrease as the compounds progress from giant ionic in structure to simple molecular.

- Ionic chlorides form neutral solution form neutral solutions in water. Covalent chlorides are hydrolysed by water and form acidic solutions.