Metals :-
Group 1A - Alkali metals ( highly reactive metals)
Non-metals :-
Group 17 - Halogens ( highly reactive non-metals )
I hope you are able to find your answer through the guidance of this site as I have yet to cover this topic in chemistry: http://scientifictutor.org/1021/chem-how-to-convert-between-grams-and-molecules/
__ KClO₃ → __ KCl + __ O₂
Left Side:
1 K
1 Cl
3 O
Right Side:
1 K
1 Cl
2 O
Since the least common multiple of 3 and 2 is 6, we need to multiply the compound with 2 oxygen by 3 and the compound with 3 oxygen by 2.
This gives us 2KClO₃ → __ KCl + 3O₂.
However, this equation is still not balanced.
Left Side:
2 K
2 Cl
6 O
Right Side:
1 K
1 Cl
6 O
In order to balance the K and Cl, we need to multiply the KCl compound on the right side by 2.
2KClO₃ → 2KCl + 3O₂