A CHEMICAL SHOWS THE TYPES OF WHAT ATOMS IN THE SMALLEST REPRESENTATIVE UNIT OF A SUBSTANCE?

Answer 1

Not sure that I understand the question.

"In chemistry and physics, an atom is the smallest particle still characterising a chemical element."

It is possible to have a long discussion over how many atoms (1,2 etc) of a chemical element might be required to demonstrate properties characterising an element.

Answer 2

a chemical formula shows the types and_ of atoms in the smallest representative unit of a substance