What's an atom?

Science

an atom itself is made up of three tiny kinds of particles called subatomic particles:proton neutron and electron. it is a fundamental piece of matter. In a normal (neutral) atom the number of protons and the number of electrons are equal. Often, but not always, the number of neutrons is the same, too.

Answer: the basic units of matter and the defining structure of elements/Smallest part of an element that can still retain the properties of that element