Alkali Metals (Group 1)

  • The Groups 1 metals need to lose an electron to obtain a full octet of electrons, and thus these would have a +1 charge.
  • These metals have got low densities, are very ductile and are silvery grey in colour.
  • The reactivity of the metals increases down a group, due to the increase of the number of shells, making the electrons further away from the nucleus, and therefore easier to be lost.

Three common reactions of the groups 1 metals are with Oxygen, water and chlorine. It must be noted that two reactions will be followed with water, that of the true metal and the metal oxide.

Oxygen

4Na + O2 → 2Na2O

A simple reaction involving a group 1 metal and Oxygen.

Water

2Na + 2H2O → 2NaOH + H2

Na2O + H2O → 2NaOH

The two reactions yield sodium hydroxide as a product but in the first reaction, there is a displacement of the Hydrogen atom, resulting from the fact that  Sodium is much more reactive then Hydrogen.

Chlorine

K + Cl → KCl

This is a direct synthesis reaction where potassium and chlorine react to form a salt. This is a typical metal and non-metal reaction.

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