Within a periodic group of transition elements the possibility of exhibiting maximum oxidation state increases with atomic number. Why?
(i) Cr3+ = 1s2 2s2 2p6, 3s2 3p6 3d3
(ii) Cu+ = 1s2, 2s2, 2p6, 3s2, 3p6, 3d10
(iii) Co2+ = 1s2, 2s2, 2p6, 3s2, 3p6, 3d7
(iv) Mn2+ = 1s2, 2s2, 2p6, 3s2, 3p6, 3d5
(v) Pm3+ = 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6 4f4
(vi) Ce4+ = 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6.
(vii) Lu2+ = 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6 4f14, 5d1.
(viii) Th4+ = 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p6, 4d10, 4f14, 5s2, 5p6, 5d10, 6s2, 6p6.