Indium

Indium,  ₄₉In

General properties
Name, seembol	indium, In
Appearance	sillery lustrous gray
Pronunciation	/ˈɪndiəm/ IN-dee-əm
Indium in the periodic cairt
Ga ↑ In ↓ Tl cadmium ← indium → tin
Atomic nummer (Z)	49
Group, block	group 13, p-block
Period	period 5
Element category	puir metal
Staundart atomic wicht (Ar)	114.818(1)
Electron configuration	[Kr] 4d10 5s2 5p1
per shell	2, 8, 18, 18, 3
Pheesical properties
Phase	solid
Meltin pynt	429.7485 K ​(156.5985 °C, ​313.8773 °F)
Bylin pynt	2345 K ​(2072 °C, ​3762 °F)
Density near r.t.	7.31 g/cm3
when liquid, at m.p.	7.02 g/cm3
Triple pynt	429.7445 K, ​~1 kPa
Heat o fusion	3.281 kJ/mol
Heat o vapourisation	231.8 kJ/mol
Molar heat capacity	26.74 J/(mol·K)
vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1196 1325 1485 1690 1962 2340
Atomic properties
Oxidation states	3, 2, 1 (amphoteric oxide)
Electronegativity	Pauling scale: 1.78
Atomic radius	empirical: 167 pm
Covalent radius	142±5 pm
Van der Waals radius	193 pm
Miscellanea
Crystal structur	​tetragonal
Speed o soond thin rod	1215 m/s (at 20 °C)
Thermal expansion	32.1 µm/(m·K) (at 25 °C)
Thermal conductivity	81.8 W/(m·K)
Electrical resistivity	83.7 n Ω·m (at 20 °C)
Magnetic orderin	diamagnetic
Young's modulus	11 GPa
Mohs haurdness	1.2
Brinell haurdness	8.83 MPa
CAS Nummer	7440-74-6
History
Discovery	Ferdinand Reich an Hieronymous Theodor Richter (1863)
First isolation	Hieronymous Theodor Richter (1867)
Maist stable isotopes o indium
iso NA hauf-life DM DE (MeV) DP 113In 4.29% - (SF) <24.281 115In 95.71% 4.41×1014 y β− 0.495 115Sn
Decay modes in parentheses are predictit, but hae nae yet been observed

Indium is a chemical element wi seembol In an atomic nummer 49. This rare, very saft, malleable an easily fusible puir hivy metal is chemically seemilar tae gallium an thallium, an shaws intermediate properties atween these twa. Indium wis discovered in 1863 an named for the indigo blue line in its spectrum that wis the first indication o its existence in zinc ores, as a new an unkent element. The metal wis first isolatit in the follaein year. Zinc ores continue tae be the primary soorce o indium, whaur it is foond in compoond form. Very rarely the element can be foond as grains o native (free) metal, but these are nae o commercial importance.