# What do atomic numbers represent?

Mar 26, 2016

#### Answer:

The atomic number, $Z$, is the number of positively charged particles within the nucleus.

#### Explanation:

So $Z$ defines the identity of the element, if $Z$ $=$ $1$, the element is hydrogen; if $Z$ $=$ $3$, the element is lithium; if $Z$ $=$ $23$, the element is vanadium.

Do you have to remember these numbers? NO, because for every exam you sit in chemistry or physics you MUST be supplied with a copy of the Periodic Table.

So, if $Z$ represents the number of positively charged nuclear particles, how many electrons, negatively charged particles does the neutral element contain?