10. a) What is the maximaum amount of iron (III) oxide than can be produced when 255 g of iron (II) sulfide arereacted with 71.4 g of oxygen gas in a closed container to produce iron (III) oxide and sulfur dioxide gas? b) What mass of the excess reactant remains after the reaction?

chemical properties are the characteristic of matter which can only be observed by changing the chemical identity of a sample like flammability reactivity and toxicity.

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.