Indium

49
In
Group
13
Period
5
Block
p
Protons
Electrons
Neutrons
49
49
66
General Properties
Atomic Number
49
Atomic Weight
114.818
Mass Number
115
Category
Post-transition metals
Color
Silver
Radioactive
No
From the brilliant indigo line in its spectrum
Crystal Structure
Centered Tetragonal
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.
Electrons per shell
2, 8, 18, 18, 3
Electron Configuration
[Kr] 4d10 5s2 5p1
In
When it is bent, indium emits a high-pitched 'cry'
Physical Properties
Phase
Solid
Density
7.31 g/cm3
Melting Point
429.75 K | 156.6 °C | 313.88 °F
Boiling Point
2345.15 K | 2072 °C | 3761.6 °F
Heat of Fusion
3.26 kJ/mol
Heat of Vaporization
230 kJ/mol
Specific Heat Capacity
0.233 J/g·K
Abundance in Earth's crust
0.000016%
Abundance in Universe
3×10-8%
Ingot
Image Credits: Images-of-elements
Ingot of 40 grams of indium
CAS Number
7440-74-6
PubChem CID Number
5359967
Atomic Properties
Atomic Radius
167 pm
Covalent Radius
142 pm
Electronegativity
1.78 (Pauling scale)
Ionization Potential
5.7864 eV
Atomic Volume
15.7 cm3/mol
Thermal Conductivity
0.816 W/cm·K
Oxidation States
1, 2, 3
Applications
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.
Indium is considered to be of low toxicity
Isotopes
Stable Isotopes
113In
Unstable Isotopes
97In, 98In, 99In, 100In, 101In, 102In, 103In, 104In, 105In, 106In, 107In, 108In, 109In, 110In, 111In, 112In, 114In, 115In, 116In, 117In, 118In, 119In, 120In, 121In, 122In, 123In, 124In, 125In, 126In, 127In, 128In, 129In, 130In, 131In, 132In, 133In, 134In, 135In