Question

exam 1: atomic theory/structure
possible points: 3.33
an isotope of oxygen contains 8 protons, 10 neutrons, and 8 electrons. what is the mass number?
8
26
16
18

Explanation:

Step1: Recall mass - number formula

Mass number = Protons + Neutrons

Step2: Substitute values

Mass number = 8 + 10 = 18

Answer:

D. 18