Lanthanum Element (Periodic Table)

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Lanthanum

Lanthanum (La) is a chemical element of the periodic table, located in the period 6, and has the atomic number 57. It is the first element in the lanthanide series. It is a soft, silvery-white metal, whose name comes from the Greek word “lanthanein”, which means to lie hidden. It is a highly reactive metal and is counted as one of the rare earth elements.

group
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
period
1
 1
H
 2
He
2
 3
Li
 4
Be
 5
B
 6
C
 7
N
 8
O
 9
F
 10
Ne
3
 11
Na
 12
Mg
 13
Al
 14
Si
 15
P
 16
S
 17
Cl
 18
Ar
4
 19
K
 20
Ca
 21
Sc
 22
Ti
 23
V
 24
Cr
 25
Mn
 26
Fe
 27
Co
 28
Ni
 29
Cu
 30
Zn
 31
Ga
 32
Ge
 33
As
 34
Se
 35
Br
 36
Kr
5
 37
Rb
 38
Sr
 39
Y
 40
Zr
 41
Nb
 42
Mo
 43
Tc
 44
Ru
 45
Rh
 46
Pd
 47
Ag
 48
Cd
 49
In
 50
Sn
 51
Sb
 52
Te
 53
I
 54
Xe
6
 55
Cs
 56
Ba
 72
Hf
 73
Ta
 74
W
 75
Re
 76
Os
 77
Ir
 78
Pt
 79
Au
 80
Hg
 81
Tl
 82
Pb
 83
Bi
 84
Po
 85
At
 86
Rn
7
 87
Fr
 88
Ra
 104
Rf
 105
Db
 106
Sg
 107
Bh
 108
Hs
 109
Mt
 110
Ds
 111
Rg
 112
Cn
 113
Nh
 114
Fl
 115
Mc
 116
Lv
 117
Ts
 118
Og
57
La
 58
Ce
 59
Pr
 60
Nd
 61
Pm
 62
Sm
 63
Eu
 64
Gd
 65
Tb
 66
Dy
 67
Ho
 68
Er
 69
Tm
 70
Yb
 71
Lu
89
Ac
 90
Th
 91
Pa
 92
U
 93
Np
 94
Pu
 95
Am
 96
Cm
 97
Bk
 98
Cf
 99
Es
 100
Fm
 101
Md
 102
No
 103
Lr
– f block

FAQs on Lanthanum Element

Lanthanum
‣ What does lanthanum look like?

Appearance: silvery white
‣ When was lanthanum discovered and by whom?

Discovery: Carl Gustaf Mosander (1838)
‣ Where is lanthanum found on the periodic table?

Lanthanum Periodic Table

Location: Lanthanum is found in the sixth row of the periodic table, next to the barium element.
‣ What is the atomic number of lanthanum?

Atomic number (Z): 57
‣ What is the symbol of lanthanum?

Symbol: La
‣ What is the atomic weight of lanthanum?

Standard atomic weight: 138.90547
‣ Lanthanum belongs to which block?

Block: f-block
‣ What period is lanthanum found?

Period: 6
‣ What is the atomic radius of lanthanum?

Atomic radius: empirical: 187 pm
‣ Lanthanum covalent radius: 207±8 pm
‣ What is the melting point of lanthanum?

Melting point: 1193 K (920 °C, 1688 °F)
‣ What is lanthanum boiling point?

Boiling point: 3737 K (3464 °C, 6267 °F)
‣ How many electron shells does lanthanum have?

Electrons per shell: 2, 8, 18, 18, 9, 2
‣ What is the electron configuration for lanthanum?

Electron configuration: [Xe] 5d1 6s2
‣ What is lanthanum ionization energy?

Ionization energies:
1st: 538.1 kJ/mol
2nd: 1067 kJ/mol
3rd: 1850.3 kJ/mol
‣ Is lanthanum a solid, liquid or gas?

Phase (at r.t): solid
‣ What is the density of lanthanum?

Density (near r.t): 6.162 g/cm3
when liquid (at m.p): 5.94 g/cm3
‣ Lanthanum magnetic ordering: paramagnetic
‣ Lanthanum natural occurrence: primordial
‣ Oxidation state of lanthanum: +3
‣ Electronegativity for the element lanthanum

Electronegativity: Pauling scale: 1.10
‣ Lanthanum poisson’s ratio: α form: 0.280
‣ Lanthanum heat of fusion: 6.20 kJ/mol
‣ Lanthanum heat of vaporization: 400 kJ/mol
‣ Lanthanum molar heat capacity: 27.11 J/(mol K)
‣ Lanthanum molar magnetic susceptibility: +118.0 × 10-6 cm3/mol (298 K)
‣ Speed of sound in lanthanum: 2475 m/s (at 20 °C)
‣ What is the crystal structure of lanthanum?

Crystal structure: double hexagonal close-packed (dhcp)
‣ Thermal expansion of lanthanum: α, poly: 12.1 µm/(m.K) (at r.t)
‣ Thermal conductivity of lanthanum: 13.4 W/(m.K)
‣ Lanthanum electrical resistivity: α, poly: 615 nΩ.m (at r.t)
‣ Lanthanum hardness

Mohs hardness: 2.5
Vickers hardness: 360-1750 MPa
Brinell hardness: 350-400 MPa
‣ Young’s modulus of lanthanum: α form: 36.6 GPa
‣ Shear modulus of lanthanum: α form: 14.3 GPa
‣ Bulk modulus of lanthanum: α form: 27.9 GPa
‣ Lanthanum CAS number: 7439-91-0

‣ Lanthanum vapor pressure

Vapor pressure (extrapolated)
P (Pa)1101001 k10 k100 k
at T (K)200522082458277231783726

‣ How many isotopes does lanthanum have?

Main isotopes of lanthanum
IsotopeAbundanceHalf-life (t1/2)Decay modeProduct
137Lasyn6 × 104 yε137Ba
138La0.089 %1.05 × 1011 yε
β–		138Ba
138Ce
139La99.911 %stable

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