Download Rules for Calculating Protons, Neutrons, Electrons, Atomic Number

Rules for Calculating Protons, Neutrons, Electrons,
Atomic Number and Atomic Mass
The ATOMIC NUMBER, PROTONS, and ELECTRONS are always the
same. EX) If the atomic number of an atom is 15, then the number of
protons is 15 and the number of electrons is 15.
To calculate the number of NEUTRONS in an atom, you take the
ATOMIC NUMBER and SUBTRACT is from the ROUNDED ATOMIC
MASS to the nearest whole number. EX) The atomic number for Zinc is
30 and the atomic mass is 65.39. So…you round the atomic mass to 65
and subtract atomic number 30 for it. 65 atomic mass – 30 atomic
number = 35 NEUTRONS.
To calculate the ATOMIC MASS of an atom you take the number of
PROTONS and ADD that to the number of NEUTRONS. EX) 6
NEUTRONS + 5 PROTONS = AN ATOMIC MASS OF 11 (amu)