Question

If an atom loses a neutron, what happens to the overall electric charge

Answer 1

the atomic mass lowers

Answer 2

Alright, this is really simple:

For atoms, all you need to know this. You have a nucleus, which is compromised of protons and neutrons. Electrons orbit the nucleus.

Protons have a positive charge of +1
Neutrons have a neutral charge
Electrons have a negative charge of -1

Now, neutrons are part of the nucleus, meaning they add overall mass/weight to the atom. If you were to take one of these away, it would STILL be the same element. Elements are defined truly by their protons, not neutrons.

So, take away a single neutron, the mass will lower, but it would still be the same element.

~Hope this helps!