Explain why isotopes of the same element behave differently in nuclear reactions but not in chemical reactions.

An isotope is a chemical structure that is highly similar to its parent isotope, with the difference lying in the number of neutrons that the compound has. As an example, carbon has the elemental number 6, which means it has 6 protons. 12-carbon will have 6 protons and 6 neutrons, while 14-carbon will have 6 protons and 8 neutrons. The differing neutron numbers will have an affect on the nuclear reactions between these two compounds, but their chemical reactions will remain the same as the neutrons will not affect how they perform on a chemical level. 

Abbreviated as mg-25.