Element 45

Rhodium (Rh)

Transition metal · Period 5 · Group 9 · d-block

Rhodium (Rh) is element 45 of the periodic table, a transition metal in period 5, group 9 (d-block) with an atomic mass of 102.91 and is a solid at standard conditions.

At a glance

Atomic number
45
Symbol
Rh
Atomic mass
102.91 u
Category
Transition metals
Period
5
Group
9
Block
d-block
Phase at STP
solid

Electron structure

Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 5s1
Shorthand configuration
[Kr] 4d8 5s1
Electrons per shell
2, 8, 18, 16, 1
Oxidation states
-3, -1, +1, +2, +3, +4, +5, +6

Physical properties

Melting point
2237 K
Boiling point
3968 K
Density
12.41 g/cm3
Phase
solid

Atomic properties

Electronegativity (Pauling)
2.28
Atomic radius
173 pm
Covalent radius
142 pm
First ionization energy
720 kJ/mol
Electron affinity
110 kJ/mol

Notable isotopes

IsotopeMassAbundanceStability
Rh-103102.9055100%Stable

Common uses

  • Catalytic converters
  • Jewelry
  • Electrical contacts
  • Mirrors

Discovery

Year
1803
Discovered by
William Hyde Wollaston
Country
England

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