Al

Sn

Ag

Zn

Absorption of light from UV range

Emission of light

Presence of unpaired electrons in s and $p$ orbitals

Complimentary colours to the absorbed light

13 electrons have spin in one direction and 16 electrons in other direction

14 electrons have spin in one direction and 15 electrons in other direction

All the electrons have spin in one direction

None of the above

$ext{CrO}_3$

$ext{Cr}_2ext{O}_3$

$ext{CrO}$

$ext{CrO}_2$

Gold oxide

Gold perchlorate

Gold nitride

AuCl

${\left( {{\rm{N}}{{\rm{H}}_4}} \right)_2}{\rm{Mo}}{{\rm{O}}_4}$

$\left( {{\rm{N}}{{\rm{H}}_4}} \right){\rm{Mo}}{{\rm{O}}_2}$

${\left( {{\rm{N}}{{\rm{H}}_4}} \right)_2}{\rm{Mo}}{{\rm{O}}_3}$

${\rm{N}}{{\rm{H}}_4}.12{\rm{Mo}}{{\rm{O}}_3}$

1.60 Å

1.40 Å

1.06 Å

0.85 Å

Al

Zn

Ni

Fe

$Mn > Cr > Ti > V$

$Ti > V > Cr > Mn$

$Cr > Mn > V > Ti$

$V.Mn > Cr > Ti$

Be

Fe

Mo

Cr

Ce⁴⁺, Yb²⁺

Gd³⁺, Tb⁴⁺

Eu²⁺, Lu³⁺

Ce⁴⁺, Eu²⁺