Firstly, before we find out the properties of alkali metals, we need to know what they actually are. An alkali metal is located in group 1 on the periodic table which includes (top to bottom) Lithium, Sodium, Potassium, Rubidium, Caesium and Francium. Although on some periodic tables hydrogen is found in group 1 with the alkali metals, it has none of the properties of alkali metals which on other periodic tables it is found in the middle by itself. Alkali metals are highly reactive under standard conditions. Here are the ten properties of alkali metals.
Here are the properties of alkali metals:
- All alkali metals have only one electron in their outer shell.
- Highly reactive.
- Tarnish easily.
- Low melting points.
- Low densities.
- Mostly silver coloured, except metallic-caesium which has a gold tint.
- Reactive aggressively with halogens to form ionic salts.
- React with water to form alkaline hydroxides.
- Alkali metal (s) + water (aq) → Alkali metal hydroxide (s) + hydrogen (g)
- The vigour of reaction increases down the group to the point that francium has to be stored in mineral oil or kerosene as by itself, it will react with air and literally explode.
- Have a high electropositivity.
Alkali metals form a very wide range of amalgams and because of this they tend to form ionically bonded salts with most electronegative elements on the periodic table such as sodium chloride and caesium fluoride.