The nuclei of most atoms contain multiple protons. Each proton has a positive charge. If objects that have like charges repel each other, why do the protons in the nuclei of most atoms not fly apart?

Explanation:

The nucleus of an atom contains both proton(s) and neutron(s). The protons are positively charged while the neutrons have no charge; hence the nucleus is positively charged. Generally, like charges repel, thus protons in the nucleus should ordinarily repel each other and fly apart in the nucleus but there is a stronger force (than the electrical force) that pulls the protons and neutrons toward each other (at some distance and does not bind them together). This force is known as the nuclear force.

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.