Fe2O3 + 3(CO) --> 3(CO2) + 2Fe 1. Calculate the mass in grams of CO2 produced when 1.08 moles of Fe2O3 reacts.
2. Calculate the mass in grams of CO required to produce 1.34 moles of Fe.
3. Calculate the number of moles of CO required to produce 0.45 grams of Fe.
4. Calculate the number of moles of Fe2O3 required to produce 3.07 grams of CO.
5. Calculate the number of moles of CO required to react with 6.01 g of Fe2O3.

so you see if you take the triangularity of the moon divided by a circle you will get the 5 1/2 and add that to 1+1 you get ur answer.

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.