What is in between the electrons and nucleus of an atom?

In between the electrons and nucleus of an atom lies the atomic nucleus which contains positively charged protons and neutral particles known as neutrons. The electrons are negatively charged particles which orbit the nucleus in shells or energy levels. The attraction between the positively charged nucleus and negatively charged electrons keeps the electrons in orbit around the nucleus. However, the electrons are also held in place by a quantum mechanical force known as the electromagnetic force, which is responsible for the chemical properties of atoms. The space between the nucleus and electrons is mostly empty space, with occasional interactions mediated by the weak nuclear force.