Definition - What does Atom mean?
An atom is the smallest constituent of a material which is considered to be a building block of it. Many atoms combine together to form a molecule which in turn combines with various other molecules to form objects around us. The size of an atom is very minuscule and on a short scale, it is approximately a ten billionth of a meter.
Petropedia explains Atom
An atom contains three particles, which are, electrons, protons and neutrons. Electrons have a negative charge and get combined with other molecules during a chemical reaction. Similarly, protons are positively charged and neutrons have no charge, i.e., they are neutral. The structure of every atom is in a way that protons and neutrons cluster together and form the central part of an atom whereas electrons form the outermost part of atom and revolve around the protons and neutrons. The central part of atom is known as a nucleus.