Findthe odd one outwith reason:
a. Cutting of nails,breaking of glass,formation of iron sulphide.
b.Permanent,reversible,change in composition.
c.Alloying ,galvanization ,crystallisation.
d.Burning of:
coal
magnesium
hydrogen
a.formation of sulphide because it is a chemical change. b.reversible because it is a physical change. c.crystallization because it is formation of crystals of substances. d.hydrogen because it forms water.