Using the periodic table, how would you determine the number of neutrons in 16 O?
How does this help us?
Well, we have the
the mass number is the number on the top-left of each element symbol that represents the sum of the number of protons and neutrons.
as stated in the question, this is
the proton number is the number of protons and the number of electrons in the atom (not added together). this is on the bottom-left of each element symbol.
number of neutrons = mass number - proton number
therefore there are 8 neutrons.