In which of the following pairs are both the ions coloured in aqueous solution ?
(At. no. : $Sc = 21, Ti = 22, Ni = 28,$$ Cu = 29, Co = 27$)
$Ni^{2+}, Cu^+$
$Ni^{2+}, Ti^{3+}$
$Sc^{3+}, Ti^{3+}$
$Sc^{3+}, Co^{2+}.$
Amongst $TiF_6^{2-}$ , $CoF_6^{3-}$ , $Cu_2Cl_2$ and $NiCl_4^{2-}$ the colourless species are
While filling up of electrons in the atomic orbitals, the $4 s$ orbital is filled before the $3 d$ orbital but reverse happens during the ionisation of the atom. Explain why?
Which of the following compounds is not colored yellow ?
Which is not true for transition elements
Assertion : Magnetic moment of $Dy$ is highest among lanthanoids.
Reason : Orbital motion contributes magnetic moment.