Lanthanum Element (Periodic Table)

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

.
.
.

Related:

Also Read:

Leave a Comment