How to Obtain the Number of SubAtomic Particles

How to Obtain the Number of Sub-Atomic Particles in an Atom Using a Periodic Table + - ++ + + + = 8 - - Protons Neutrons + Electrons - Equal to the atomic # on the Periodic Table Equal to the atomic mass (rounded to a whole #) minus the # of protons Equal to the # of protons Example: Determine the # of protons, neutrons, and electrons in an atom of oxygen. Protons = 8 (Atomic #) Neutrons = 8 (Rounded atomic mass minus atomic #) Neutron Calculations = 16 (P + N) – 8 (P) = 8 N Electrons = 8 (# of P)

How to Obtain the Number of Sub-Atomic Particles in an Ion Using a Periodic Table - - - 2 - Notice how two electrons have been gained by the atom, thus resulting in an ion + = 8 ++ + + + - = 8 - = 10 8 - Neutrons Protons + Equal to the atomic # on the Periodic Table - - - Electrons - Equal to the atomic mass (rounded to a whole #) minus the # of protons Equal to the # of protons plus the # in the upper right corner if followed by a (-) OR minus the # in the upper right corner if followed by a (+) Example: Determine the # of protons, neutrons, and electrons in the oxygen ion O²¯. Protons = 8 (Atomic #) Neutrons = 8 (Rounded atomic mass minus atomic #) Neutron Calculations = 16 (P + N) – 8 (P) = 8 N Electrons = 10 Electron Calculations = 8 (e) + 2 (e) = 10