Question

The atom of an element has $10$ electrons, $10$ protons and $12$ neutrons. Find the mass number of the element:

• A. $10$
• B. $12$
• C. $22$
• D. $32$

Answer 1

The correct option is C $22$

The total number of protons and neutrons in the nucleus is called mass number of the atom. It is generally represented by th letter $A$.

$Mass$ $Number\left(A\right)$ = $NumberofProtons$ + $NumberofNeutrons$

As given, the atom of an element contains $10$ protons and $12$ neutrons , therefore,

$mass$ $number$ = $10$ + $12$ = $22$

So, the mass number of the element is 22.