Lanthanum (La) is a silvery-white metallic transition metal that eventually faded when exposed to air. Let us look at some lanthanum facts in detail.
The lanthanum atom was discovered by Carl Gustav Mosander. It should be included with the Lanthanides. Monazite and bastnaesite are the two rare earth crust minerals that have the highest concentrations (25% and 38%). It contains rare earth minerals that are separated by the ion exchange method.
Let us go through the fundamental chemical characteristics of lanthanum, such as its atomic radius, electronic shell, allotropic forms, and isotopes in detail.
Lanthanum symbol
An atomic symbol is used to represent an atom with one or two characters, while a molecular symbol is used to symbolise a molecule. Let us see the atomic symbol for lanthanum.
In the periodic table, the atomic symbol for lanthanum is “La”.
Lanthanum group in periodic table
The group includes the element of the same kind of bonds, identical properties and the same outermost shell. Let us check out the group in which lanthanum lies.
Lanthanum belongs to the group of lanthanides in the periodic table.
Lanthanum period in periodic table
Periods are horizontal rows and decided the position of an element and its properties. Let us check the period of Lanthanum.
Lanthanum belongs to the 6th period in the periodic table because it possesses three electrons in its valence shell.
Lanthanum block in periodic table
In the periodic table, a block is the collection of an element’s atomic orbitals where the valence electrons are located. Let us check out the block for lanthanum.
Lanthanum makes up the f block, also known as the inner-transition metal. For the reason that the valence electrons in the lanthanum atom’s outermost orbital are in the f-block.
Lanthanum atomic number
A substance’s overall number of protons in its nucleus is known as its atomic number. Let us determine the atomic number of lanthanum.
The atomic number of lanthanum is 57, meaning that there are 57 protons and 57 electrons in it.
Lanthanum atomic Weight
Atomic mass units are used to express the average mass of an element’s atoms as they appear in nature. Let us look at the Lanthanum atomic weight.
Lanthanum has an atomic weight of 138.905 u, which has a natural abundance of 99.9 % per atom, which is the average mass of all the element’s isotopes.
Lanthanum Electronegativity according to Pauling
When an atom links with another atom, its relative capacity to draw election density toward itself is measured as its E.N. Let us check the electronegativity of lanthanum.
The value of lanthanum’s electronegativity is 1.10 on the scale measured using the Pauling scale.
Lanthanum atomic Density
The density, measured in cm3, is the number of atoms or nuclides present in a substance’s unit volume. Let us calculate the atomic density of lanthanum.
Lanthanum has an atomic density of 6.146 g/cm3 when it is at standard temperature. It becomes 5.94 g/cm3 dense when it melts or reaches its melting point. The atomic density of lanthanum is computed by dividing its mass by volume.
Lanthanum melting point
The difference between vapour pressure and the transformation of a substance from a solid to a liquid is called the melting point. Let us determine the lanthanum melting point.
The melting point of lanthanum is 920 °C (1193 K, 1688 °F).
Lanthanum boiling point
A substance has achieved its boiling point when the vapour pressure reaches that of atmospheric pressure. Let us find the boiling point of lanthanum.
The Lanthanum atom has a boiling point of 3464 °C (3737 K, 6267 °F).
Lanthanum Vanderwaals radius
Two unbonded atoms are separated by a distance that is halved when their electrostatic forces are equal is called vanderwaals radius. Let us check the vanderwaals radius of Lanthanum.
Lanthanum has a vanderwaals radius of 240pm. It has an empirical atomic radius in the range of 2.43 Å or 187 pm (1pm=1*10‑12 m). Lanthanum thus has the biggest atomic radii.
Lanthanum ionic radius
The radius of an ion’s nucleus up to which it can affect its electron cloud is known as the ionic radius. Let us check the ionic radius of Lanthanum.
The effective ionic radius of lanthanum in the +3 state is 1.16 Å(117.2pm), and the ionic radius of its crystal is 103.2 pm.
Lanthanum isotopes
The mass number of isotopes distinguishes them from one another. Let us identify the isotopes of lanthanum.
Lanthanum has 39 radioisotopes present. There are two known found-in-nature isotopes of lanthanum. Lanthanum-138 and Lanthanum-139 are these two isotopic substances. Following is a table of the most common lanthanum isotopes:
| Isotopes of Lanthanum | Atomic number | Atomic mass | Half-life | Decay mode | Daughter isotope | Excitation energy |
| 137La | 57 | 136.906494 | 6×104 y | EC | 137Ba | Stable |
| 138La | 57 | 137.907112 | 1.02×1011 y | β+ (66.4%) β− (33.6%) | 138Ba 138Ce | 72.57keV |
| 139La | 57 | 138.9063533 | Stable | Stable | Stable | Stable |
Lanthanum electronic shell
The electronic shells that surround the nucleus each contain a specific number of electrons. Let us discuss the electronic shell made of lanthanum.
An electronic shell structure of Lanthanum is 2,8,18,18,9,2 around a nucleus that has the s, p, and d orbital, respectively.
Lanthanum energy of first ionisation
The amount of energy required to remove the outer shell electrons from the last orbital is known as the first I.E. Let us look at the first Ionization energy of Lanthanum.
Lanthanum requires 538.1 kJ/mol of energy for the first ionisation to remove the electrons from its 5d orbital or last shell that consists of two electrons.
Lanthanum energy of second ionisation
The 2nd I.E is the force needed to free the most loosely bound electron from a species with a positive charge of (1+). Let us find out the second ionization energy of Lanthanum.
The second ionisation energy of lanthanum is 1067 kJ/mol. This value can be achieved by the removal of additional electrons from the 6s orbital which changes from 6s2 →6s1 in its electronic structure.
Lanthanum energy of third ionisation
A third ionisation involves removing two outermost electrons from an element’s orbital with a +2 oxidation state. Let us find out Lanthanum’s third ionisation energy.
Lanthanum requires 1850.3 kJ/mol of energy. This energy is used to remove the third electrons from the 6s orbitals which change from 6s1 →6s0 orbitals in its electronic configuration.
Lanthanum oxidation states
The oxidation state describes how much an atom has oxidised (lost electrons) in a chemical complex. Let us check the oxidation states of the lanthanum.
Lanthanum exclusively has the oxidation state +3 in compounds. The white oxide La2O3 is the most alkaline rare-earth oxide because it has the highest ionic radius among rare-earth R3+ ions. It also shows 0,+1,+2 oxidation states.
Lanthanum electron configurations
An element’s electron configuration explains how the electrons are dispersed throughout its atomic orbitals. Let us examine the electronic configuration of the lanthanum.
The electronic configurations of lanthanum are 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 5d1 6s2 4f0 or [Xe] 5d1 6s24f0. The first number in this equation represents the fundamental quantum number, the letter an orbital, and the last number the total number of electrons.
Lanthanum CAS number
The CAS number is a particular variation of the number, which is a distinctive identity number issued globally. Let us check the CAS number of Lanthanum.
The CAS number of the lanthanum molecule is 7439-91-0.
Lanthanum ChemSpider ID
Each chemical element is given a unique, particular number called a “Chem Spider ID” by the Royal Society of Chemistry. Let us see the Chemspider ID of Lanthanum.
The Chem Spider ID is 22369 for lanthanum. The CAS number is a unique identifier for each element.
Lanthanum allotropic forms
Allotropic forms exhibit the same chemical composition as other molecular forms of the element, but different physical properties. Let us discuss the lanthanum allotrope.
Lanthanum exists in three structurally different allotropic forms. At 310 °C, lanthanum changes from a hexagonal to a face-centred cubic structure, and at 865 °C, it changes once more to a body-centred cubic structure. The table below shows lanthanum in its allotropic form:
| Allotropic form | Temperature | Structure type | Lattice Value |
| α-phase | At room temperature | Double close-packed hexagonal structure | a = 3.7740 Å c = 12.171 Å |
| β-phase | At 325 °C (617 °F) | Face-centred cubic structure | a = 5.303 Å |
| γ-phase | At 887 °C (1,629 °F) | Body-centred cubic structure | a = 4.26 Å |
Lanthanum chemical classification
Chemical elements are categorised based on their reactivity and other properties. Let us take a look at lanthanum’s chemical properties.
The following list of chemical characteristics of lanthanum is given below:
- Hydrogen gas is stored in a lanthanum-nickel alloy for use in hydrogen-powered vehicles.
- When left at room temperature, the lanthanum compound tends to oxidise in the presence of oxygen and transform into La2O3.
- Except for hydrofluoric acid, La typically reacts slowly with water and dissolves more readily in diluted acids (HF).
Lanthanum state at room temperature
A suitable temperature range indoors is referred to as the “room temperature,” which is normally between 20 and 25°C. Let us check the state of Lanthanum at room temperature.
At room temperature, lanthanum is solid. The lanthanide with the lowest volatility is lanthanum.
Is Lanthanum paramagnetic?
A small magnetic field supplied externally to some materials causes paramagnetism. Let us check whether the Lanthanum is paramagnetic or not.
Lanthanum is a very less paramagnetic character because it has empty 4f orbitals. The unpaired electrons in all trivalent lanthanide ions cause them to be paramagnetic. Unlike the following lanthanides, which are substantially paramagnetic, lanthanum does not have strong paramagnetism.
Conclusion
Lanthanum metal is created when calcium and anhydrous fluoride are combined. In the top crust of the Earth, lanthanum makes up about 0.0018% of the composition. Electrodes for gas tungsten arc welding use lanthanum oxides in place of radioactive thorium.
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