Question

If xenon has an atomic number of 54 and a mass number of 108, how many neutrons does it have?

A. 54
B. 27
C. 100
D. 108

Short answer

Xenon will have 54 neutrons. The correct answer is option A.

Step-by-step solution

Introduction

Atoms of each of the elements possess a characteristic number ofelectrons and protons. Theatomic number of an element is the number of protons present within that element, it is used by scientists to differentiate one element from the other. The number of neutrons is variable, which results in the formation of isotopes. In combination, the number of neutrons and protons determines the mass number of an element.

Explanation

The sum of the numbers of neutrons and protons present within the nucleus of an atom is known as themass number of the element. In the given question, it is described that the atomic number of Xenon is54, which indicates that the number of protons present within it is 54. However, its mass number is 108, which shows that there are 54 protons and 54 neutrons present within the element. Hence, Xenon will have 54 neutrons.