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

Apr 8, 2018

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.

Apr 8, 2018

$146$

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