74.62 g of magnesium oxide is formed from 45.00 g magnesium so 74.62-45.00= 29.62 g of oxygen is consumed or in other words a new compound is formed in the burning of magnesium in oxygen with a heavier mass than the pure magnesium.
you can google it and it pops up right away
Electrolysis and heat can separate a compound into its elements.
I hope this helped you!
Personal experience from Ag Mech classes-Concrete cools faster than metal.
