Indium

Indium (In)

Soft silvery element belonging to group 13 of the periodic table. The most common natural isotope is In-115, which has a half-life of 6*10^4 years. Five other radioisotopes exist. Discovered in 1863 by Reich and Richter.
Atomic Number49
Atomic Weight114.818
Mass Number115
Group13
Period5
Blockp
Protons49 p+
Neutrons66 n0
Electrons49 e-
Indium wetting glass.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
155 pm
Atomic Volume
Covalent Radius
142 pm
Metallic Radius
142 pm
Ionic Radius
62 pm
Crystal Radius
76 pm
Van der Waals radius
193 pm
Density
7.31 g/cm³
Boiling Point
2,353 K
Melting Point
429.32 K
Electrons per shell2, 8, 18, 18, 3
Electronegativity
1.78
Electrophilicity
0.8439965667135 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
5.7863552 eV/particle
Heat of Vaporization
225.1 kJ/mol
Heat of Fusion
3.24 kJ/mol
Heat of Formation
243 kJ/mol
Molar Heat Capacity
26.74 J/(mol K)
Specific Heat Capacity
0.233 J/(g⋅K)
Thermal Conductivity
81.8 W/(m K)
Gas Basicity
Dipole Polarizability
65 a₀
C6 Dispersion Coefficient
779 a₀
Oxidation States1, 2, 3
Color
Silver
Crystal StructureCentered Tetragonal (TET)
Lattice Constant
4.59 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Kr] 4d10 5s2 5p1
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryPost-transition metals, Poor metals
CAS GroupIIIB
IUPAC GroupIIIA
Glawe Number80
Mendeleev Number84
Pettifor Number79
Geochemical Class
Goldschmidt Classchalcophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
0.25 mg/kg
Abundance in Oceans
0.02 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe3×10-8%

Isotopes of Indium

Stable Isotopes
113In 115In
Unstable Isotopes
97In 98In 99In 100In 101In 102In 103In 104In 105In 106In 107In 108In 109In 110In 111In 112In 114In 116In 117In 118In 119In 120In 121In 122In 123In 124In 125In 126In 127In 128In 129In 130In 131In 132In 133In 134In 135In

History

Ferdinand Reich and Hieronymous Theodor Richter first identified indium in sphalerite by its bright indigo-blue spectroscopic emission line. As no element was known with a bright blue emission they concluded that a new element was present in the minerals. Richter went on to isolate the metal in 1864. From the brilliant indigo line in its spectrum

DiscoverersFerdinand Reich, T. Richter
Discovery LocationGermany
Discovery Year1863
Name OriginLatin: indicum (color indigo), the color it shows in a spectroscope.
Indium is considered to be of low toxicity
When it is bent, indium emits a high-pitched 'cry'

Uses

Indium's current primary application is to form transparent electrodes from indium tin oxide in liquid crystal displays and touchscreens. It is widely used in thin-films to form lubricated layers. It is also used for making particularly low melting point alloys, and is a component in some lead-free solders. Used to coat high speed bearings and as an alloy that lowers the melting point of other metals. Relativly small amounts are used in dental items and in electronic semiconductors.

Sources

Found in certain zinc ores.