Question

How many neutrons does element X have if its atomic number is 25 and its mass number is 92?

Answer 1

Atomic mass is the sum of neutrons and protons, and atomic number is the number of protons.
Therefore, 92-25 = 67.

67 neutrons.

Sidenote:
Electrons are not considered in atomic mass since they weigh way too little

Answer 2

Atomic mass is the sum of neutrons and protons, and atomic number is the number of protons.
Therefore, 92-25 = 67.

67 neutrons.

Sidenote:
Electrons are not considered in atomic mass since they weigh way too little