Question

the sum of relative atomic mass of four nitrogen atoms is equal to the relative formula mass of XO. what is X ?

Answer 1

Answer:

Calcium.

Explanation:

Atomic mass of nitrogen = 14 u.

4 such atoms = 56 u.

Atomic mass of oxygen ( O ) = 16 u.

So, let x be the atomic mass of element X.

56 = x + 16

x = 40

The element with atomic mass of 40 u is calcium ( Ca ).