What is unique about an elements structure?

What makes an element unique?

All atoms have protons, electrons and neutrons, but what makes each element unique is the number of protons. For instance, a helium atom has 2 protons. ... The number of protons in an atom is known as the atomic number.

Explanation:

Each element has its own unique properties. Each contains a different number of protons and neutrons, giving it its own atomic number and mass number. The atomic number of an element is equal to the number of protons that element contains.

catya that's not even a b or c

there are two significant figures.