What is an atomic number?

1 Answer
anor277
Mar 22, 2016

The atomic number, #Z#, is the number of protons, massive positively charged particles, contained in the element's nucleus.

Explanation:

#Z# defines the identity of the element. If #Z# #=# #1#, the element is hydrogen; if #Z# #=# #2#, the element is helium; if #Z# #=# #19#, the element is potassium; if #Z# #=# #92#, the element is uranium.

How do I know this? Well, in every examination of chemistry and physics you will ever sit, you will be given a Periodic Table, which lists the atomic number and atomic mass of EVERY element. Of course, you will have to be able to use the table, so get cracking.

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