Elements
57

La

Lanthanum

Lanthanum (La) is a soft silvery white coloured metal that has the atomic number 57 in the periodic table. It is a Lanthanide metal. It has the symbol La.

Lanthanum is classed as a rare earth metal much like Yttrium. It was discovered by Carl Mosander in 1839 in the mineral cerite. Moander took some finely powdered Cerium nitrate and mixed it with nitric acid, upon separating out the solid he obtained a brick red oxide. It was not until 1923 that pure Lanthanum was obtained by electrolysis. Much like the alkali metals Lanthanum can be cut with a knife and oxidises quickly and is reactive with water. Lanthanum is used in rechargeable batteries and as a catalyst to crack petroleum fractions. It is a solid metal at room temperature with a melting point of 920°c and a boiling point of 3464°c.

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FAQ's

What is the Melting Point for Lanthanum?

Lanthanum has a Melting Point of 918°F, meaning at 918°F it will turn to a liquid.

What is the Boiling Point for Lanthanum?

Lanthanum has a Boiling Point of 3464°F, meaning at 3464°F it will turn to a Gas.

What is the Electronegativity of Lanthanum?

Lanthanum's Electronegativty is 1.1. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

What is the Heat of Vaporization of Lanthanum?

Lanthanum has a Heat of Vaporization of 414 kJ/mol.

Uses

It is used in the electodes of high-intensity, carbon-arc lights. Also used in the production of high-grade europium metal. Because it gives glass refractive properties, it is used in expensive camera lenses.

Sources

Found with rare earths in monazite and bastnasite. Monazite sand typicall contains 25% lanthanum.

57
Protons
57
Electrons
82
Neutrons

La

Element Symbol
La
Atomic Weight
138.905
Atomic Number
57
State
Solid
Melting Point
Unknown
918
°C
Boiling Point
3464
Unknown
°C
Heat of Vaporization
414
Unknown
kJ/mol
Crystal Structure
Hexagonal
Thermoconductivity
0.135
Unknown
W/cmK
Shells
2,8,18,18,9,2
Group
Lanthanide
Period
6
Block
F Block
Orbitals
[Xe] 5d1 6s2
Coefficient of Thermal Expansion
5.2 10^-6 K^-1
Covalent Radius
1.69 Å
Density at 293K
6.7 g/cm³
Electrical Conductivity
0.0126 10^6/cm ohm
First Ionization Potential
5.5770 V
Second Ionization Potential
11.059 V
Third Ionization Potential
19.174 V
Ionic Radius
1.16 (+3) Å
Oxydation States
3
Lattice Parameter
3.770 Å
Lattice Parameter 2
--
Lattice Parameter 3
--
Pronounced

LAN-the-nem

Discovered by

Carl Mosander

Discovery date

1839

Orbital configuration
2,8,18,18,9,2

Download the Periodic Table

Explore Other Lanthanides

140.116
58

Ce

Cerium
174.967
71

Lu

Lutetium
157.25
64

Gd

Gadolinium
173.045
70

Yb

Ytterbium
144.24
60

Nd

Neodymium
164.93
67

Ho

Holmium
158.925
65

Tb

Terbium
145
61

Pm

Promethium
151.964
63

Eu

Europium
168.934
69

Tm

Thulium
162.5
66

Dy

Dysprosium
167.259
68

Er

Erbium
150.36
62

Sm

Samarium
140.908
59

Pr

Praseodymium
The lanthanide series contains 15 metallic elements from number 57 (lanthanum) to 71 (lutetium). They are located in group 3 and in the f-block of period six in the periodic table.
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Barium

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Cerium

58