What is the basic unit of matter.?
There are about 100 or so different types of atoms, i.e. elements, which are all conveniently listed on the Periodic Table. Each individual atom contains massive particles with positive charge, and negatively charged particles with ZERO rest mass, that are conceived to whizz about the positively charged nuclear core. The number of positively charged particles in the nucleus gives
Exchange and sharing of electrons between atoms defines all of chemical bonding, and thus all of chemistry.