If an element has an atomic number of 7 and an atomic mass n

If an element has an atomic number of 7 and an atomic mass number of 15, how many protons, neutrons, and electrons does it possess?

a) 7 protons, 8 neutrons, and 7 electrons

b) 7 protons, 8 neutrons, and 8 electrons

c) 8 protons, 7 neutrons, and 8 electrons

d) 15 protons, 8 neutrons, and 8 electrons

Solution

Number of electrons = Number of protons = Atomic number = 7

Number of neutrons = Mass number - atomic number = (15-7) = 8

Therefore, the correct answer is option a.