Answer
86 protons and 136 neutrons
Work Step by Step
Atomic number of the isotope $^{222}_{86}Rn$ = 86 = $Z$
Mass number of $^{222}_{86}Rn$ = 222 = $A$
So, number of protons = Atomic number = 86
Number of neutrons = $A - Z = 222 - 86$ = 136