Which statements describe elements? Elements can be separated using physical means.
Elements are made of atoms with the same atomic number.
Elements cannot be separated using ordinary chemical means.
Elements may be represented by chemical symbols.
Elements are made of two or more different types of atoms.

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.

a physical change biology

explanation: