Question

give one example of displacement reaction, decomposition and combination reaction with explaination

Answer 1

displacement rxn:more reactive metal displaceses the less reactive metal.
eg:Fe+cuso4=fe2so4+cu.

decomposition rxn:exchange of four such ions between the reactant.
eg: bacl2+na2so4=baso4+nacl.
combination rxn:two reactant gives one product.
eg:h2+o2= h2o.

Answer 2

Fe+cuso4->feso4+cu displacement
ca+h2o->can(oh)2 combination
agcl->ag+cl2 decomposition