Coloured salts are formed by
Alkali metals
Lanthanides
Actinides
Transition metals
Which of the following pair of transitional elements exhibit highest and lowest density
Which of the comparison regarding $Zn,\,Cd,\,Hg$ is/are incorrect ?
$(I)$ $ZnCl_2$ is ionic whereas $CdCl_2$ and $HgCl_2$ are covalent
$(II)$ $Zn$ and $Cd$ dissolves in dilute acid $(HCl)$ liberating $H_2$ but $Hg$ can not
$(III)$ $Zn$ and $Cd$ forming with ppt. of $Zn(OH)_2$ and $Cd(OH)_2$ but $Hg$ forms coloured ppt. of
$(IV)$ all from $A_2^{2+}$ type ion
Which is not amphoteric
For the first row transition metals the ${E^\Theta }$ values are:
${E^\Theta }$ | $V$ | $Cr$ | $Mn$ | $Fe$ | $Co$ | $Ni$ | $Cu$ |
$\left( {{M^{2 + }}/M} \right)$ | $-1.18$ | $-0.91$ | $-1.18$ | $-0.44$ | $-0.28$ | $-0.25$ | $+0.35$ |
Explain the irregularity in the above values.
An oxide of copper which is red in colour has the formula