The number of electrons in the atom of an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of an atom of this element?

The correct option is A

${}_{15}^{31}\text{X}$

Given that, number of electrons in element X = 15 and number of neutrons = 16

Atomic number = number of protons = number of electrons in neutral atom = 15

Mass number = number of protons + number of neutrons = 15 + 16 = 31

Thus, the atom is represented as ${}_{15}^{31}\text{X}$.