What is the empirical formula of feso3

Iron has two ionic states of +2 and + 3. The formula for iron oxide with the Fe + 2 is FeO. The formula for iron oxide with The Fe+3 is Fe2O3. Using the atomic mass of Fe as 55.845 gr/mole and O as 15.999 gr/mole the percent Fe of FeO is 77.73% and of Fe2O3 is 69.94%.

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my expliantion is not available

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.