La (Lanthanum) is an element with position number 57 in the periodic table.
Located in the VI period. Melting point: 920 ℃. Density: 6.16 g/cm3.
The order of filling the orbitals with electrons in the La atom is an exception to the rule.
Expected electronic configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f1
But in reality, one electron moves from the 4f orbital to the 5d orbital:
Electronic configuration of the Lanthanum atom in ascending order of orbital energies:
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d1
Electronic configuration of the Lanthanum atom in ascending order of the levels:
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 5d1 6s2
Reduced electronic configuration La:
[Xe] 5d1 6s2
Expected electronic configuration
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f1
But in reality, one electron moves from the 4f orbital to the 5d orbital:
Electronic configuration of the Lanthanum atom in ascending order of orbital energies:
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d1
Electronic configuration of the Lanthanum atom in ascending order of the levels:
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 5d1 6s2
Reduced electronic configuration La:
[Xe] 5d1 6s2
Below is the electronic diagram of the Lanthanum atom
Distribution of electrons over energy levels in the La atom
1-st level (K): 2
2-st level (L): 8
3-st level (M): 18
4-st level (N): 18
5-st level (O): 9
6-st level (P): 2
1-st level (K): 2
2-st level (L): 8
3-st level (M): 18
4-st level (N): 18
5-st level (O): 9
6-st level (P): 2
Oxidation states of Lanthanum: +2, +3
Other elements
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Electronic configurations of other elements
Barium (Ba) electron configurationCerium (Ce) electron configuration
Electronic configuration table
