What do you think about alkali metals ?
The alkali metals are all highly reactive and are never found in elemental form in nature. As a result, in the laboratory they are stored under mineral oil or paraffin oil. They also tarnish easily and have low melting points and densities. Potassium and rubidium possess a weak radioactive characteristic due to the presence of long duration radioactive isotopes.
The alkali metals are silver-colored (caesium has a golden tinge), soft, low-density metals, which react readily with halogens to form ionic salts, and wit ...more