Give an example of silvery-white metal.

Silvery white metals:-

1. Lanthanides and actinides are the groups of elements that are present below the main section of the periodic table.
2. They are very reactive in nature.
3. When they react with water in cold conditions, they liberate hydrogen gas$\left({\mathrm{H}}_2\right)$ slowly, being an exothermic reaction, it burns easily in the air.
4. These are silvery-white metals.
5. They form oxides when left in exposure to air, and get tarnished.
6. Some examples involve lanthanum(La), and actinium(Ac).

Therefore, lanthanides and actinides are silvery-white metals, for example, lanthanum (La), and actinium (Ac).