* Physical Change: A physical change alters the appearance or form of a substance, but not its chemical composition. Examples include melting ice (water remains H₂O), cutting paper (paper is still cellulose), or boiling water (still H₂O).
* Chemical Change: A chemical change results in the formation of new substances with different chemical properties. This often involves breaking and forming new chemical bonds.
What happens when you heat ZnO?
ZnO is a white solid. When heated, it undergoes a decomposition reaction:
ZnO(s) → Zn(s) + 1/2 O₂(g)
Here's what happens:
* The heat provides enough energy to break the chemical bonds holding the zinc and oxygen atoms together in ZnO.
* This results in the formation of solid zinc (Zn) and gaseous oxygen (O₂).
* The original ZnO is no longer present, and new substances are formed.
Therefore, since new substances are formed, heating zinc oxide is a chemical change.
