lightest metal is__________?

lightest metal is__________?A. Lithium
B. Sodium
C. Magnesium
D. Aluminium

The lightest or least dense metal that is a pure element is lithium, which has a density of 0.534 g/cm3. This makes lithium nearly half as dense as water, so if lithium was not so reactive, a chunk of the metal would float on water.