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 $Cr =24$ )
All these are colourless.
All these are coloured.
Only $Ni ^{2+}$ is coloured and $Zn ^{2+}$ and $Cr ^{3+}$ are colourless.
Only $Zn ^{2+}$ is colourless and $Ni ^{2+}$ and $Cr ^{3+}$ are coloured.
Chloride of which of the following element is coloured
Which of the following pair both compounds have no exsistance
The chief constituents of steel made in India are
Which of the following is not correct about transition metals
Which of the following has second ionisation potential less than expected