What is an atom? what are electrons, protons, and neutrons?

An atom is the building block of all matter. Electrons, protons and neutrons make up the atom. protons and neutrons make up the nucleus of the atom, and the electrons are on the electron shell.

Atom is the basic unit of a chemical element. An electron is the negative charge in every atom. A proton is the positive charge of every atom. A neutron is neutral.

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.