Question

Which of the following describes an atom?

A). 6 protons, 6 neutrons in the nucleus, and 6 electrons in the electron cloud

B). Hydrogen chemically combined with an oxygen

C). Smallest units of two hydrogen joined together

Answer 1

you might have more help asking this in chemistry tab

Answer 2

Hey, now, there's such a thing as atomic physics ;)

An atom is the smallest possible unit of a chemical element.

That doesn't mean atoms themselves aren't made up of smaller things: in fact, one of your answers describes what a Carbon-12 atom is made of.

Answer 3

A.