Which quantum number determines the energy of an electron in a hydrogen atom?

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.

Which electron configuration represents the electrons in an atom of sodium in the ground state at stp