You could consider the chemical reaction, (Al2S3 → 2 Al + 3S) or you could simply realize that since the Al would be written as a monatomic atom in the balanced equation and since there are 2 Al’s in the compound, there must be a 2:1 ratio
You could consider the chemical reaction, (Al2S3 → 2 Al + 3S) or you could simply realize that since the Al would be written as a monatomic atom in the balanced equation and since there are 2 Al’s in the compound, there must be a 2:1 ratio