Elements

Elements

Learn this definition it should be just fine:

"Elements consist of ONE TYPE of ATOM only"

So what makes elements different? It's how many protons it has. So, take helium for example. Helium has 2 protons, so any element with 2 protons will be helium. It gets no choice in this. *whip noise*

Every element has these 2 things, learn them:

Mass Number:
The number at the top left of the element. This tells you the total number of protons and neutrons in the atom.

Atomic Number:

The number at the bottom left of the element. How many protons are in the atom? That's what this number tells you.

So in summary:

Top number = number of protons and neutrons. (mass number)

Bottom number = Number of protons. (atomic number)

Since I didn't put a picture in, have this one:

That cat be lovin'.