Answer:
D
Step-by-step explanation:
KClO3 ==> KCl + O2
1 K 1
1 Cl 1
3 O 2
There are a different amount of oxygen atoms so this equation is not balanced
KClO3 ==> 3KCl + O2
1 K 3
1 Cl 3
3 O 2
None of the elements have the same number of atoms on either side of the equation therefore this equation is not balanced.
2KClO3 ==> KCl + 3O2
2 K 1
2 Cl 1
6 O 6
The number of potassium atoms and chlorine atoms is different on both sides of the equation therefore this equation is not balanced.
2KClO3 ==> 2KCl + 3O2
2 K 2
2 Cl 2
6 O 6
The number of atoms of each element are the same on both sides therefore this equation is balanced.