Question

An atom has mass number $23$ and atomic number $11$. How many protons, electrons and neutrons are present in the atom?

• A. $11,12,13$
• B. $11,11,12$
• C. $11,11,13$
• D. $11,14,15$

Answer 1

The correct option is B $11,11,12$

$\left(B\right)$ $11,11,12$

$Given$ - Mass number of atom = $23$

Atomic number of atom = $11$

As, no. of electrons in an atom is equal to an atomic number of the element.

So, number of electrons = $11$

Secondly , number of protons are equal to number of electrons.

so, number of protons = $11$

And number of neutrons = mass number - atomic number = $23-11$ = $12$

so, number of neutrons = $12$

So , the atom contains $11protons$, $11electrons$, $12neutrons$.