An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus?
A)19
B)13
C)7
D)6

Question

Quizplus · Accepted Answer

The number of neutrons in the nucleus can be found by subtracting the atomic number (which represents the number of protons in the nucleus) from the mass number (which represents the total number of protons and neutrons in the nucleus).

Number of neutrons = Mass number - Atomic number 
Number of neutrons = 13 - 6 = 7

Therefore, the answer is C) 7.

An Atom's Mass Number Is 13 and Its Atomic Number