The combustion of propane may be described by the chemical equation C3H8(g)+5O2(g)⟶3CO2(g)+4H2O(g)

How many grams of O2(g) are needed to completely burn 25.7 g C3H8(g)?

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium

C) the increase in atmospheric pressure pushes the walls of the balloon outward thus making it  is the answer.hope i you.