Question

why does number of neutrons increase relative to protons with increase in mass number ?

Answer 1

"mass number=no. of protons+no. of neutrons".So as u see,when there is increase in mass no. there has to be increase in either proton no. or neutron no. OR increase in both numbers of proton as well as neutron in relative or same amount. hence when there is relative increase of neutrons to protons this increases mass number.

Answer 2

that's obvious...but no. of neutrons increases more than that of proton...why so ?

Answer 3

An increase in the atomic mass of something, can only occur through extra neutrons. An atom of something with extra neutrons is called an isotope. An atom of something with extra protons is an atom of something else.

Also isotopes tend to be more common among the heavier elements. So these extra neutrons are more commonly found in elements of high atomic mass.

Answer 4

i'm still confused

Answer 5

I think the easiest way to think about it without going into great detail is to think about the 4 freshman forces. The important ones are the strong nuclear force and the electromagnetic force. Since protons have a positive charge and (opposites attract) like repels, there is a lot of repelling going on. What you need is the strong nuclear force that holds nucleons (protons and neutrons) together and adding neutrons increases this force without the side effects of charge. As you add more protons your repulsion gets bigger so you add more neutrons to keep one force from overcoming the other.

This is way simplified especially when you consider the unified forces and meson exchange but that is the general idea.