Question

How many neutrons does Uranium-238 have if it has 92 protons?

Answer 1

See explanation.

Explanation:

The mass number is `238`, so the nucleus has `238` particles in total, including `92` protons.

So to calculate the number of neutrons we have to subtract:

`238-92=146`

Answer: The atom has `146` neutrons.

Answer 2

`146`

Explanation:

The mass of uranium-`238` is `238` mass units. The total mass of an element is the sum of its protons and neutrons.

There are `92` protons in this isotope, and its mass is `238`, so that means that there are,

`238-92=146` neutrons