Achemist is studying the properties of a gas under various conditions. he observes that when the gas is at room temperature and low pressure, it behaves as an ideal gas. when the gas is cooled to 10 kelvin and is placed under high pressure, however, it deviates significantly from an ideal gas. explain these observations

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.