Answer:
Chemical change.
Explanation:
Physical Change
The changes that occur only due to change in shape or physical properties but their chemical or internal composition remain unchanged.
Example :
Water converting to Ice
Water converting to gas
In this water molecule remain the same only they rearrange themselves that change its state of mater not composition
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
These changes occur due to chemical reactions
These may not be observed with naked eye
Example:
Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood
The reaction of between sodium and chlorine:
2Na(s) + Cl₂(g) -------------------------------------> 2NaCl(s)
