Question

The atomic number of an element is more important to the chemist than its relative atomic mass why

Answer 1

If you know the atomic no. Of an element you can find out its max. Properties such as group no. Block no oxidation state melting point boiling point electronic configuration and many more.
Therefore we say it many times that atomic number is the Base to the periodic properties of an element.

Hope you get your answer.

Answer 2

Helloo!!

The atomic number of an element is more important to the chemist than its relative atomic mass because Relative atomic mass is generally not used for calculation in chemistry that's why it's not so important.

hope it helps