Answer:
Since moles are just "some number of particles", and since one O2 molecule contains enough oxygen for two H2O molecules, you need 2.5 moles of O2 for 5 moles of H2O.
Chemical is the answer your looking for.
Answer: 1.414x10^24 molecules in 94.4g MgO
Explanation: molar mass MgO 40.204
molecules in 40.204 g MgO = avogadro number
molecules in 94.4 g MgO = (94.4/40.204)*avogadro number
(94.4/40.204)*6.02214076*10^23 = 14.14x10^23
They both have two electron shells. Period indicates number of shells.
