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49In114.818
Indium
Post-Transition MetalIndium is a chemical element with symbol In and atomic number 49. It is a post-transition metallic element that is rare in Earth's crust. The metal is very soft, malleable and easily fusible, with a melting point higher than sodium, but lower than lithium or tin.
Phase: SolidAppearance: silvery lustrous gray
2, 8, 18, 18, 3
Physical Properties
Atomic Mass114.8181 u
Density7.31 g/cm³
Melting Point429.7485 K
Boiling Point2345 K
Molar Heat26.74 J/(mol·K)
Period5
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p1
Semantic Config[Kr] 4d10 5s2 5p1
Shells2, 8, 18, 18, 3
Electron Affinity37.043 kJ/mol
Electronegativity1.78
Ionization Energies
IE1: 558.3 kJ/molIE2: 1820.7 kJ/molIE3: 2704 kJ/molIE4: 5210 kJ/mol
Discovery
Discovered byFerdinand Reich