Which is the atomic number of an alkali metal?
10
11
12
13

11 is the atomic number of alkali metal

Explanation:

The Group 1 elements are called the alkali metals. ... All the Group 1 elements are very reactive . They must be stored under oil to keep air and water away from them. Group 1 elements form alkaline solutions when they react with water, which is why they are called alkali metals.

c (diamond),

sio2 (quartz)

fe 55.85 g/mol and h2o 18.02 g/mol.