The wave mechanical model of the atom is required to explain the

Wave-mechanical theory suggests that every electron that circles the nucleus of an atom comprises a particular orbital and rotates in a certain direction, but the orbital is just like cloud or wave of energy

Explanation:

Wave-mechanical model, suggesting that the electrons are much like wave of energy as particles. They are moving so quickly that at a certain time they are not really in any position, and in response to fields around them they constantly change their course.

Wave-mechanical theory suggests that every electron that circles the nucleus of an atom comprises a particular orbital and rotates in a certain direction, but the orbital is just like cloud or wave of energy

this is poiselle's equation from fluid mechanic in physics. mech eng