What does the term atomic number refer to? 

A)  the number of atoms in a molecule 
B)  the number of protons in an atom 
C)  the number of electrons in an atom 
D)  the number of neutrons in a molecule

Atomic Number

A fundamental characteristic of elements, representing the number of protons in the nucleus of an atom, which determines the chemical properties of the element.

Protons

Positively charged particles found within the nucleus of an atom.

Electrons

Subatomic particles with a negative electric charge, found in all atoms and acting as the primary carrier of electricity in solids.