Why are relative atomic masses on the periodic tables not whole numbers?

Question

Chemistry

Adriana Camacho

13 July, 01:43

Why are relative atomic masses on the periodic tables not whole numbers?

+1

Answers (2)

Know the Answer?

Halle Benton · Answer 1

They are averages.

Explanation:

atomic numbers on periodic tables are derived from the average value of all the isotopes of the element. So being averages they are sometimes not integers.

Desirae Richardson · Answer 2

The sum of the number of protons and neutrons in an atom is called the mass number. Atomic mass is never an integer number for several reasons: The atomic mass reported on a periodic table is the weighted average of all the naturally occurring isotopes. Being an average it would be most unlikely to be a whole number.