Section 2.3

Question 1

The number of protons

in an atom of any particular element is called

Answer 1

that element’s atomic number

Question 2

the number of protons plus neutrons in the atom

Answer 2

Mass number

Question 3

Atoms with identical atomic numbers but different mass numbers (that is, same
number of protons but different numbers of neutrons) are called

Answer 3

Isotopes