How many neutrons does element X have if its atomic number is 39 and its mass number is 79?

Question

asked Jul 19, 2019 82.7k views

1 Answer

Allen M · Answer 1 · 2019-07-23T01:25:57+0000

Number of neutrons: atomic mass - atomic number

Element X's atomic mass is 79 and its atomic number is 39. Subtract 39 from 79 to find how many neutrons Element X has.

79 - 39 = 40

Element X has 40 neutrons.