(a(i))[1]
Complete the electronic configuration for a chromium atom. $1s^2 2s^2 2p^6 3s^2$ \dots
(a(ii))[1]
State the two highest oxidation states commonly shown by chromium in its compounds.
(b(i))[2]
Six compounds or complexes, H, J, K, L, M and N, are produced when excess aqueous NH$_3$, aqueous NaOH and concentrated aqueous HCl are each added separately to different solutions containing Cu$^{2+}$(aq) or Co$^{2+}$(aq). State the colours of the following compounds or complexes: H, K and M.
(b(ii))[2]
Write the formulae for the following compounds or complexes: L and N.
(b(iii))[1]
State the appearance shown by compound J.