The number of protons and neutrons in the nucleus : 92 and 146
Further explanation
Given
Mass number = 238
Atomic number = 92
Required
Protons and neutrons
Solution
Mass number=number of protons + neutrons
Atomic number=number of protons=number of electrons
Atomic number = 92⇒number of protons=92
Number of neutrons = mass number - atomic number
Number of neutrons = 238 - 92 = 146