Nothingness is a term for describing what precedes the Big Bang or follows the Big Crunch - a zerolarity rather than a singularity.
Quantum physics contends that physical reality is reducible to two fundamental things - matter (notably solids, liquids and gases) and forces (notably electromagnetism, gravity, and two nuclear forces). Either type of reality can ultimately be described in terms of particles. That is, all physical matter is ultimately reducible to two types of fermion particle - quarks and leptons - while the four physical forces (potential energy fields) are reducible to bosons, i.e. virtual messenger particles.
A slight diversion: matter is anything that has both mass and volume (i.e. occupies space, like an object). In this respect, Einstein famously pointed out that E = mc-squared - meaning that energy is equivalent to mass multiplied by the speed of light. In short, a tiny atom of matter consists of a hell of a lot of energy. This explains the power of the nuclear bomb, when particles of certain atoms are split and their energy released.
Anyway, to recap, quantum physics tells us that reality (matter/mass and energy/forces) are reducible to three types of elementary particle: quarks, leptons and bosons.
Regarding nothingness, it is hereby jypothesised that the main relevant elementary particles include the nothon, nothitron, no-on, and noton.
The Nothon: the quark of nothingness
The Nothitron: the lepton of nothingness (a.k.a. the negnothingon)
The No-on and Noton: the lower and higher bosons of nothingness.
The Nothingon: this is the composite particle of nothingness, comprised of nothons held together by no-ons. The nothingon has both a positive form (posnothingon) and a neutral form (neutnothingon)
The Natom: this is an atom of nothingness, comprised of a nucleus of two types of nothingon - posnothingons and neutnothingons - surrounded by a shell of orbiting nothitrons. Nothingons and nothitrons are held together by notons
[Note: Jypothesis = jocular hypothesis]