Answer:
Copper turns green on exposure to air
Explanation:
Liquid water freezes to form ice: Physical change
Reason: Water can melt back when it becomes ice.
Copper turns green on exposure to air: Chemical change
Reason: The copper can not change back from the green state when it turns green.
Answer:
option c is correct
Explanation:
the addition of catalyst does not effect the position or equilibrium constant and increase the forward and backward reaction in equal rates so no effect would be observed
CO2 and H2O are compounds hope this helped :)