👉 In physics, a subexcitation is a state of an atom or molecule where there are fewer electrons than the number of protons. This means that the atoms or molecules have less energy and can be more stable under certain conditions. Subexcitations occur when the total number of electrons in an atom or molecule is not equal to its proton number. For example, a hydrogen atom has 1 electron (proton) and therefore no subexcitations. However, if an atom contains two protons