Question: what is an atom

Caroline Roche answered on 18 Mar 2025:

An atom is the basic building block of all matter.
It consists of neutrons (neutral particle) & protons (positive particle) at the center with an orbit of electrons (negative particle) around it – the number of each is what is described as it’s atomic structure.
The number of protons is what decides what element it is (it’s atomic number), the neutrons decide what isotope of that element it is – the most common version of that element is what usually appears on the periodic table.