The fundamental particle of quantum mechanics is the electron, as describing its motion and energetics is the goal of the Schrödinger equation. What is the fundamental particle of molecular mechanics? 1. It is the same – the electron. 2. It is the atom. 3. It is the molecule. 4. The Fermi boson. 5. There are no particles. Solution In the molecular mechanics there are the following properties: The atom is taken as one particle every particle(atom) has a radius, mostly a van der walls radius It(atom) can be polarized (atom) Has a constant net charge Bonds(between atoms) are treated as springs with an equilibrium distance known as bond length Since all these relate to an atom, Thus an atom is the fundamental particle of molecular mechanics. .