S-Cool Revision Summary

S-Cool Revision Summary

A group in the Periodic Table contains elements with the same outer shell electronic configuration but with differing proton numbers.

Periodic variations may be observed across Periods in physical properties such as ionisation energies, atomic radii, boiling points and electrical conductivities.

Across a Period the structures of the elements change from giant metallic, through giant molecular to simple molecular. Group 0 consists of individual atoms.

Chemically, the elements change from reactive metals, through less reactive metals and less reactive non-metals to reactive non-metals. Group 0 are highly unreactive.

There are periodic variations in the formulae and properties of oxides and chlorides of elements, from ionic compounds in Group I to molecular covalent compounds in Group VII.

Across Period 3, the trend in the reactions of the elements and their oxides and chlorides with water shows decreasing pH in the solutions formed.

Across Period 3 there is a general trend from the formation of a strongly alkaline solution by the ionic oxide in Group I, to the formation of increasingly acidic solutions by the molecular oxides of Group V to VII.

Between these two extremes lie the basic oxide of Group II, the insoluble amphoteric oxide of Group III and the insoluble but acidic oxide of Group IV.

All the chlorides of Period 3 elements dissolve readily in water. Across the Period there is a general trend of increasing speed of reaction and increasing acidity of the solution.