Many elements have non-integral atomic masses because

Options

A. they have isotopes
B. their isotopes have non-integral masses
C. their isotopes have different masses
D. the constituents, neutrons, protons and electrons, combine to give fractional masses

Answer

A, C

Explanation

Many elements have several isotopes. For such elements, atomic mass is average of the atomic masses of different isotopes, which is usually non-integral.