Which of the following statements incorrectly uses Avogadro's number? 1. There are 6.022 X1023 carbon atoms in a mole of carbon.
2. There are 6.022 X1023 sodium atoms in a mole of sodium carbonate, Na2CO3.
3. There are 6.022 X1023 formula units in a mole of sodium carbonate, Na2CO3.
4. There are 6.022 X1023 molecules in a mole of carbon dioxide, CO2.

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.