How many neutrons are present in a stable atom of aluminum?

1 Answer
May 30, 2016

There must be 14 neutrons is a typical stable atom of aluminum.


Look at the periodic table:

1) The atomic number is 13, thus 13 protons.

2) the atomic mass is close to 27 indicating that most naturally occurring Al (which would be a stable isotope if one exists) had a mass number of 27. Thus protons plus neutrons = 27.

The difference between these two numbers is the number of neutrons.

Wikipedia stated that a small amount of Al-26 occurs in nature but decays to magnesium.