Any help please Find groups G and H and a surjective homomorphism ?: G rightarrow H such that Z(G) Z(H) Solution When is the abelianization map, you get lots of examples. For example: Let G be the group of quaternions: {±1, ±i, ±j, ±k} Let be the map: :G--->G/{±1} = H {±1} is the commutator subgroup of G, and so the result is the abelianization of G, which is isomorphic to Z2 x Z2. At any rate, H is itself Abelian, so Z(H)=H. However, Z(G)={±1}, whose image under is just the identity of H. Therefore Z(G) is NOT equal to Z(H)..