Question

The mass number of an atom is $24$ and its atomic number is $11$, then which of the following statements is correct?

• A. Its nucleus contains $13$ neutrons.
• B. Its nucleus contains $0$ neutrons.
• C. Its nucleus contains $11$ neutrons.
• D. Nothing can be said.

Answer 1

The correct option is A Its nucleus contains $13$ neutrons.

Mass number is $N=24$

Atomic number $Z=11$

Number of neutrons in the nucleus is $N-Z=13$