When the equation #Li + O_2 -> Li_2O# is correctly balanced, what is the sum ofthe coefficients?
The coefficients are selected so as to represent the conservation of mass. Is mass conserved in the given reaction? If it is not then it cannot be accepted as a representation of chemical reality. To make the arithmetic a bit easier we could write.........
See this old answer.......
Interestingly, lithium metal is one of the few materials that will react with (otherwise inert!) dinitrogen gas to give lithium nitride,
How would balance this equation?