$Cu(CN)_4^{2 - }$ is colourless as it absorbs light in
Visible region
Ultraviolet region
Infrared region
All above are wrong
Which forms coloured salts
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
For the ions $Zn ^{2+}, \,Ni ^{2+}$ and $Cr ^{3+}$ which among the following statements is correct ?
(Atomic number of $Zn =30,\,Ni =28$ and $Cr =24$ )
Paris green is
Bessemer converter is used in the manufacture of