Question

With an isolated hydrogen atom as an example, what would happen if the strong force suddenly ceased?

Answer 1

The proton would split up into three quarks.

Explanation:

The proton is made of three quarks: one down-quark and two up-quarks. They are held together by the strong interaction. If you ceased it, the electromagnetic force would be the only one that matters. The two up-quarks would be pulled towards the down quark beacuse of the different electric charge, and would be pushed away from each other because of their same electric charge.