They show variable oxidation states.

Their compounds are often colored.

They often exhibit catalytic activity.

They have completely filled d subshells in all their oxidation states.

Always solid

Highly coloured alloys

Alloys which contain mercury as one of the contents

Compounds of mercury

Their compounds are generally coloured.

They can form ionic or covalent compounds.

Their melting and boiling points are high.

They do not exhibit variable valency.

${\rm{T}}{{\rm{i}}^{3 + }}$

${\rm{F}}{{\rm{e}}^{3 + }}$

${{\rm{V}}^{2 + }}$

${\rm{Z}}{{\rm{n}}^{2 + }}$

$Mn^{2+}$

$Fe^{2+}$

$Co^{2+}$

$Ni^{2+}$

${\rm{ZnC}}{{\rm{l}}_2}$

${\rm{CuS}}{{\rm{O}}_4}$

${\rm{H}}{{\rm{g}}_2}{\rm{C}}{{\rm{l}}_2}$

${\rm{HgC}}{{\rm{l}}_2}$

All four sides of a square are equal in length.

All four angles of a square are 90 degrees.

The diagonals of a square bisect each other at 45 degrees.

The diagonals of a square are equal in length.

AgCl

${\rm{PbC}}{{\rm{l}}_2}$

${\rm{H}}{{\rm{g}}_2}{\rm{C}}{{\rm{l}}_2}$

${\rm{H}}{{\rm{g}}_2}{{\rm{I}}_2}$

Np

Cm

Pu

U

Blue

Light green

Very dark green

Yellow

$S{c^{3 + }}$

$N{i^{2 + }}$

$T{i^{3 + }}$

$Z{n^{2 + }}$