Question

using the periodic table how do you calculate neutrons

Answer 1

Assuming you want to know how many neutrons a stable element has... usually it has as many neutrons as the number of protons. So remember the periodic table tells you the number of protons... which just also happen to be the number of neutrons (most of the time)

Answer 2

You can identify the number of neutrons element by subtracting the atomic mass number from the atomic number (which can be found on the periodic table)( USE and LOOK at periodic table, it will help you greatly :)

Number of Neutrons = Mass Number - Atomic Number