Question #700fe

1 Answer
Mar 23, 2017

Answer:

Subtract the atomic number from the mass number to find the number of neutrons.

Explanation:

For example Boron has an atomic number of 5. It has a mass number of 10.8. This means that approximately 80% of Boron atoms have a mass of 11 and 20% of Boron atoms have a mass of 10.

The isotope Boron 11 #B_5^11# has 5 protons with a mass of 5 amu

# 11 - 5 = 6 # This means that the atom has 6 neutrons. While

The isotope Boron 10 # B_5^10# has 5 protons with a mass of 5 amu

# 10 - 5 = 5# This means that the atom has 5 neutrons .

The mass number is the sum of the protons and neutrons. So to find the number of neutrons subtract the protons from the mass number.