Atomic Structure. All matter is composed of atoms, each of which has a central nucleus and one or more electrons that travel in orbits around the nucleus, like satellites around the earth. The nucleus contains one or more positively charged particles called protons.

John Dalton

All matter in the Universe is made of very small particles. They are in constant motion and in constant interaction with each other. Elementary particles form atoms and atoms form molecules. There is a finite number of types of atoms in the universe which are the elements in the periodic table.

According to the ACS, chemistry is the study of matter, defined as anything that has mass and takes up space, and the changes that matter can undergo when it is subject to different environments and conditions.

There are four natural states of matter: Solids, liquids, gases and plasma.

In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter (also called the fifth state of matter) which is typically formed when a gas of bosons at low densities is cooled to temperatures very close to absolute zero (-273.15 °C, -459.67 °F).

This chilly substance was initially theorised by Albert Einstein and Satyendra Nath Bose in the early 1920s as the fifth state of matter, following solids, liquids, gases and plasma. It is a supercooled gas that no longer behaves as individual atoms and particles, but rather an entity in a single quantum state.

So particle-antiparticle pairs can be created from “nothing”, that is from no particles to two particles, but energy must be provided, so these particles can be viewed as having been created from the energy.

The end result is unknown; a simple estimation would have all the matter and space-time in the universe collapse into a dimensionless singularity back into how the universe started with the Big Bang, but at these scales unknown quantum effects need to be considered (see Quantum gravity).