What term describes atoms with different atomic masses due to varying numbers of neutrons

The term is “ISOTOPES” These describe atoms with different atomic masses.

The term which describes different atomic masses of similar atom because of varying numbers of neutrons are Isotopes.

Explanation:

The isotopes are the chemical element which has different atomic masses due to the fact that number of neutrons are not same but it has same number of proton.

When the number of neutron increases in a nucleus, with the same electronic configuration and same number of proton, element is said to have isotopes. There are may be variants of isotopes of an element. For example, hydrogen has 3 isotopes.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.