Answer:
K2CO3 = K2O + CO2
Step-by-step explanation:
In a chemical equation, the number of atoms on the left needs to be balanced with the number of atoms on the right, and there has to be the same number of the same *type* of atom on both sides as well.
On the left:
2 K
1 C
3 O
and on the right,
2 K
1 O
On the right, there are a few atoms missing, specifically, 1 C and 2 O.
The missing atoms then should be added to the side missing the atoms, preferably in a stable molecule. Luckily, CO2 contains exactly 1 C, and 2 O s, and is quite stable. So, a "CO2" has to be added on the left