What are the numbers of the subatomic particles in gold?

Sep 23, 2016

A Gold (Au) atom has 79 protons and 79 electrons. A typical gold atom has 118 neutrons, though there are 18 other radioisotopes discovered so far.

From the periodic table, a gold atom is represented by

${\textcolor{w h i t e}{}}_{79}^{197} \text{Au}$

79 is its charge (atomic number), which is both its proton number and electron number.

197 is its mass (atomic mass), which is the sum of its proton number and neutron number. The neutron number can be calculated by subtracting the proton mass from the total mass.

$197 - 79 = 118$

The mass of the electrons does not contribute significantly to the total mass of the atom and therefore can be ignored.