Balance the equation Mg+Fe2O3->MgO+Fr

3Mg + Fe2O3 - --> 3 MgO + 2Fe

Explanation:

3Mg + Fe2O3 - --> 3 MgO + 2Fe

Mg 3 Mg 3

Fe 2 Fe 2

O 3 O 3

before after

3Mg + Fe2O3 = 2Fe + 3MgO

Explanation:

Make sure the number of each element equal on both right and left hand side

Eg. There are 3 molecules of oxygen on left hand side so to balance right hand side add a 3 in front of MgO, because you've added a 3 in front of MgO you now have to add a 3 in front of Mg on the left hand side to balance it out and continue to do so for the rest of the chemical equation.