The Atom & Subatomic Particles

The atomic number represents the identity of the element and reveals the number of protons, whereas the atomic mass reveals the number of protons and neutrons. 

Structure of the Atom

The atom is the fundamental unit of an element and it’s composed of the 3 subatomic particles. 

Atomic Number vs. Atomic Mass

Concept: Discussing Atomic Number & Atomic Mass


The number of protons gives the identity of an element. Ions arise when there is an unequal number of protons and electrons. 

Example: Identify the unknown element.

Element X (8 protons, 8 electrons, 8 neutrons) 

Element Y (35 protons, 36 electrons, 46 neutrons)

Element Z (12 protons, 10 electrons, 13 neutrons)