Question

An atom of aluminum (Al) has an atomic number of 13 and a mass number of 27. How many neutrons does it have?

A) 13
B) 14
C) 27
D) 40

Answer 1

B

Atomic mass = no. of proton

Atomic mass= P +N

27= 13+N

N=14

Answer 2

Answer:

14

Explanation:

The atomic # is how many protons it has, the mass is the total number of protons (P) and neutrons (N).

P+N=M     13+N=27

27-13=14    Neutrons= 14