Given the equation C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) at 25◦C and 1.00 atm. Calcualte the following: a) ∆H◦rxn ; Is the reaction endothermic or exothermic? Explain your answer.
b) ∆S◦rxn ; Is the reaction spontaneous with respect to entropy? Explain your answer.
c) ∆G of the reaction. Is the reaction spontaneous with respect to the Gibbs Free energy? Explain your answer.

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock

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.