The overall reaction in a commercial heat pack can be represented as a. how much heat is released when 4.00 mol iron is reacted with excess o2? b. how much heat is released when 1.00 mol fe2o3 is produced? c. how much heat is released when 1.00 g iron is reacted with excess o2? d. how much heat is released when 10.0 g fe and 2.00 g o2 are?

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

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.