The solubility of silver bromide in hypo solution is due to the formation of :

Why do the transition elements exhibits variable oxidation states?

$Cu(CN)_4^{2 - }$ is colourless as it absorbs light in

${[Sc{({H_2}O)_6}]^{3 + }}$ ion is

An oxide of copper which is red in colour has the formula

Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points:

$(i)$ electronic configurations,

$(ii)$ oxidation states,

$(iii)$ ionisation enthalpies, and

$(iv)$ atomic sizes.