An atom has 13 protons and 14 neutrons. What is its mass number?

mass-number

#1

An atom has 13 protons and 14 neutrons. What is its mass number?

Answer:

Mass number of an atom is the sum of numbers of protons and neutrons. This is because the mass of electrons is much smaller then neutrons and protons, so we don’t count them in.

Answer is 13+14=27