Which of the following statements is MOST accurate regarding atoms? Most atoms cannot combine with other atoms
Atoms of the same element may have
different mass numbers
Atoms only contain protons
Chemical reactions divide atoms into
smaller units

Atoms of the same element may have different mass numbers.

Explanation:

Mass number is the number of protons + the number of neutrons in an atom. Atoms of the same element can have different number of protons, and hence different mass numbers.

Atoms of the same element with different numbers of protons (but same numbers of neutrons) are called isotopes.

Hope this helps!

the answer would be a