Question

What is the atomic number of an element?

Answer 1

The atomic number `Z` is the number of positively charged, massive nuclear particles, and defines the identity of the element.

Explanation:

If `Z=1` we have the element hydrogen, `Z=2`, helium, `Z=3`, lithium,.............`Z=24`, chromium........etc.

You won't have to remember these numbers, because for every exam you ever sit in chemistry or physics, you should be supplied with a Periodic Table as a matter of course. You still have to know how to use the Table effectively.