Question

Why is the mass of an actual element/ atom different then the number show on the periodic table?

A. The periodic table contains the mass of the most abundant isotope only
B. The periodic table contains an average mass of isotopes by abundance
C. The periodic table contains the largest mass of all isotopes
D. It is the same, the mass shown is the mass of an element/ atom

Answer 1

B.

Step-by-step explanation:

The atomic masses listed on the periodic table are a weighted AVERAGE of an element's isotopes.