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57 - Lanthanum lanthanide

Discovered by Carl Gustaf Mosander in 1839

Lanthanum

Lanthanum is a soft, ductile, silvery-white metallic chemical element with symbol La and atomic number 57. It tarnishes rapidly when exposed to air and is soft enough to be cut with a knife. It gave its name to the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table:it is also sometimes considered the first element of the 6th-period transition metals.

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
57-71 La-Lu Lanthanides
89-103 Ac-Lr Actinides
ShellElectronsOrbitals
122 in 1s
282 in 2s + 6 in 2p
3182 in 3s + 6 in 3p + 10 in 3d
4182 in 4s + 6 in 4p + 10 in 4d
592 in 5s + 6 in 5p + 1 in 5d
622 in 6s
LanthanumLaElectron 1Electron 2Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 10Electron 11Electron 12Electron 13Electron 14Electron 15Electron 16Electron 17Electron 18Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 10Electron 11Electron 12Electron 13Electron 14Electron 15Electron 16Electron 17Electron 18Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 1Electron 2
139  u Atomic Mass
2.7  Å Atomic Radius
3.74k  K Boiling Point
2.07  Å Covalent Radius
6.16  g/cm³ Density
53 Electron Affinity
1.1 Electronegativity
5.58  eV First Ionization Energy
1.19k  K Melting Point
6 Number of Shells
57 Atomic Number
2, 8, 18, 18, 9, 2 Electron Shell Occupations