Which shows how much electron is in the outer layer

What mass of carbon dioxide is produced from the complete combustion of 4.50×10−3 g of methane?

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have