Question

select the correct answer.
the atomic number of krypton (kr) is 36, and its mass number is 84. how many neutrons does it have?
a. 18
b. 36
c. 48
d. 72

Explanation:

Step1: Recall the formula for mass number

Mass number \(A=\) number of protons \(Z+\) number of neutrons \(N\).

Step2: Rearrange the formula to find the number of neutrons

\(N = A - Z\).

Step3: Substitute the given values

Given \(A = 84\) (mass number) and \(Z=36\) (atomic number, which is equal to the number of protons). Then \(N=84 - 36\).
\(N = 48\)

Answer:

C. 48