How does the process of photosynthesis create food? (a) Cells split into two new cells with the identical genetic makeup.
(b)Chloroplasts use carbon dioxide and water to create glucose.
(c)Mitochondria use oxygen to break down glucose and convert it to ATP.
(d)Waste passes through the cell membrane and leaves the cell.

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.