# Mercury has an atomic number of 80. How many electrons are there in an isotope of mercury-204?

Mar 30, 2017

80 electrons.

#### Explanation:

The number of electrons equals the number of protons in a neutral
atom. The number of neutrons has no effect on the number of electrons.

$H {g}_{80}^{204}$ has 80 protons 80 electrons and 124 neutrons.

The mass of 204 is made up of the protons and neutrons.