Which one of the following compounds is not coloured
$N{a_2}CuC{l_4}$
$N{a_2}CdC{l_4}$
${K_4}Fe{(CN)_6}$
${K_3}Fe{(CN)_6}$
In which pair of ions both are diamagnetic in nature?
Which of the following sulphides is yellow in colour
Most transition metals
$I :$ form sets of compounds which display different oxidation states of the metal
$II :$ form coloured ions in solution
$III :$ burn vigorously in oxygen
$IV :$ act as catalyst
The trivalent ion having largest size in following is
Which one of the following characteristics of the transition metals is associated with their catalytic activity