Compared to a 0.500 mole sample of Helium gas at 0.00°C and 760. mmHg, a 0.500 mole sample of
Hydrogen at 298 K and 101.3 kPa contains
A) molecules having higher average kinetic energy
B) fewer molecules
C) more molecules
D) molecules having lower average kinetic energy

your answer is c) plasma

~*"auba14"*~

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.