${\rm{M}}{{\rm{n}}_2}{\left( {{\rm{CO}}} \right)_{10}}$

$\left[ {{\rm{Cu}}{{\left( {{\rm{N}}{{\rm{H}}_3}} \right)}_4}} \right]{\rm{C}}{{\rm{l}}_2}$

${\rm{Z}}{{\rm{n}}_2}\left[ {{\rm{Fe}}{{\left( {{\rm{CN}}} \right)}_6}} \right]$

$\left[ {{\rm{Ag}}{{\left( {{\rm{N}}{{\rm{H}}_3}} \right)}_2}} \right]{\rm{OH}}$

($n - 1)\;d -$orbitals

($n - 2)\;f$-orbitals

($n - 1)\;d$-orbitals and ($n -$1) $f$-orbitals

($n - 1)\;d$-orbitals and $ns -$orbitals

Al, Cu

Zn, Cd

Pb, Sn

Zn, Al

Mn

Al

W

C

$Ti^{3+}$ and $V^{3+}$

$Cr^{2+}$ and $Fe^{2+}$

$Mn^{2+}$ and $Fe^{2+}$

$Ti^{3+}$ and $Fe^{3+}$

Blue

Light green

Very dark green

Yellow

${\rm{Ru}}{\left( {{\rm{CO}}} \right)_4}$

${\rm{Ru}}{\left( {{\rm{CO}}} \right)_5}$

${\rm{Ru}}{\left( {{\rm{CO}}} \right)_8}$

${\rm{Ru}}{\left( {{\rm{CO}}} \right)_6}$

$ext{CrO}_3$

$ext{Cr}_2ext{O}_3$

$ext{CrO}$

$ext{CrO}_2$

Ionic bonds

Covalent bonds

Ionic and covalent bonds

Ionic and coordinate bonds

${\rm{Zn}}{\left( {{\rm{OH}}} \right)_2}$

${\rm{Al}}{\left( {{\rm{OH}}} \right)_3}$

${\rm{Mg}}{\left( {{\rm{OH}}} \right)_2}$

${\rm{Ca}}{\left( {{\rm{OH}}} \right)_2}$

Hg

$\rm{Hg}_2\rm{Cl}_2$

$\rm{SnCl}_4$

$\rm{SnCl}_2$