Question

Calculate the mass number of an atom with 8 protons, 12 neutrons and 10 electrons

Answer 1

Answer: 20

Explanation: Mass number is the number of neutrons plus the number of protons. 8 + 12 gives 20.

Answer 2

Mass number

• No of protons+No of neutrons
• 12+8
• 20

Mass number is 20