What is the mass number of an atom of copper that has 36 neutrons?

solution:

since n we know that Copper has 29 protons and 36 neutrons thus

according to the mass formula is

=number of neutrons + number of protons

=36+29

=65

therefore,

Copper has 29 protons. The mass number of an isotope is the sum of the protons and neutrons. An isotope of copper with 36 neutrons will have a mass number of 65.