Question

21 if an atom has 18 protons and 22 neutrons, what is the atomic mass? a 22 b 40 c 4 d 18

Explanation:

Step1: Recall atomic mass formula

Atomic mass = number of protons + number of neutrons

Step2: Substitute given values

Atomic mass = 18 + 22

Step3: Calculate result

Atomic mass = 40

Answer:

B. 40