Lithium electron configuration is 1s2 2s1. The electron configuration of lithium shows that period of lithium is 2 and lithium is an s-block element. Lithium electron configuration and orbital diagram are the main topics of this article.
Also, period and group determination, valency and valence electrons, various reactions and compound formation of lithium, bond formation of lithium have been discussed.
Electrons are arranged in different orbitals at different distances from the nucleus of the atom according to certain rules. The arrangement of electrons at different energy levels and orbitals of an atom according to certain rules is called electron configuration.
The electron arrangement of atoms in a periodic table can be done in two ways. The third element in the periodic table is lithium. That is, the lithium electron configuration can be done in two ways.
- Electron configuration via orbit.
- Electron configuration via orbital.
Electron arrangement through orbitals is done on different principles. For example, the Aufbau principle, Hund’s principle, Pauli’s exclusion principle.
Lithium Electron Configuration through orbit
All the electrons in the atom revolve around the nucleus in a number of circular paths of a certain radius. Circular paths of this specific radius are called orbit. Orbits are expressed by ‘n’.
And the first orbit is expressed by K, 2nd orbit L, 3rd orbit M, 4th orbit N. The maximum electron holding capacity in each orbit is 2n2. [Here, n = 1,2,3,4 . . .]
n=1 for K orbit-
The maximum electron holding capacity in K orbit is 2n2 = 2 × 12 = 2 electrons.
n=2 for K orbit-
The maximum electron holding capacity in L orbit is 2n 2 = 2 × 22 = 8 electrons.
n=3 for M orbit-
The maximum electron holding capacity in M orbit is 2n 2 = 2 × 32 = 18 electrons.
n=4 for N orbit-
The maximum electron holding capacity in N orbit is 2n 2 = 2 × 42 = 32 electrons.
The atomic number of lithium atoms is 3. That is, the number of electrons in the lithium atom is 3. The electron configuration of lithium atom has 2 electrons in the first orbit and 1 electron in the 2nd orbit. The order of the lithium electron configuration through orbit and electrons per shell is 2, 1.
The electron configuration of lithium atom through orbital
Atomic energy levels are subdivided into sub-energy levels. These sub-energy levels are called orbital. The sub energy levels are expressed by l. The value of ‘l’ is from 0 to (n – 1). The sub-energy levels are known as s, p, d, f. Determining the value of ‘l’ for different energy levels is-
If n = 1,
(n – 1) = (1–1) = 0
Therefore, the orbital number of ‘l’ is 1; And the orbital is 1 s.
If n = 2,
(n – 1) = (2–1) = 1.
Therefore, the orbital number of ‘l’ is 2; And the orbital is 2s, 2p.
If n = 3,
(n – 1) = (3–1) = 2.
Therefore, the orbital number of ‘l’ is 3; And the orbital is 3s, 3p, 3d.
If n = 4,
(n – 1) = (4–1) = 3
Therefore, the orbital number of ‘l’ is 4; And the orbital is 4s, 4p, 4d, 4f.
If n = 5,
(n – 1) = (n – 5) = 4.
Therefore, l = 0,1,2,3,4. The number of orbitals will be 5 but 4s, 4p, 4d, 4f in these four orbitals it is possible to arrange the electrons of all the elements of the periodic table.
Lithium electron configuration in the Aufbau principle
The Aufbau principle is to arrange electrons through sub-energy levels. Scientist Aufbau discovered this electron configuration method. The Aufbau principle is that the electrons present in the atom will first complete the lowest energy orbital and then gradually continue to complete the higher energy orbital.
These orbitals are named s, p, d, f. The electron holding capacity of these orbitals is s = 2, p = 6, d = 10 and f = 14. The Aufbau electron configuration method is 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f . Lithium electron configuration in the Aufbau principle is 1s2 2s1.
The electron configuration of Lithium in Hund’s principle
Hund’s principle is that when electrons enter the orbitals of equal power, the electrons will randomly enter the orbital as long as the orbital is empty. And the spin of these unpaired electrons will be one-sided.
The electron configuration of lithium is 1s2 2s1. s suborbital has 1 orbital. Although the lithium atom has one unpaired electrons, the last orbital of the lithium atom is ‘s’.
Therefore, Hund’s principle does not support the entry of new electrons into the s orbital. Therefore, the lithium atom does not support the Hund principle.
Determination of group and period through the electron configuration of lithium
The last orbit of an element is the period of that element. Lithium atom electron configuration is 1s2 2s1. The electron configuration of lithium atom shows that the last orbit of the lithium atom is 2. So, the period of the lithium atom is 2.
On the other hand, the number of electrons present in the last orbit of an element is the number of groups in that element. 1 electron exists in the last orbit of the lithium atom. That is, the group number of lithium is 1. Therefore, we can say that the period of the lithium element is 2 and the group is 1.
Determination of the valency and valence electrons of lithium
The ability of one atom of an element to join another atom during the formation of a molecule is called valency. If the last orbit of an element has 1, 2, 3 or 4 electrons, then the number of electrons in the last orbit is the valency of that element.
Lithium electron configuration is Li(3) = 1s2 2s1. From the electron configuration of lithium, we can say that 1 electron exists in the last orbit(2s1) of lithium. Therefore, the valency(valence) of lithium is 1.
Again, the number of electrons in the last orbit of an element, the number of those electrons is the valence electrons of that element. In the lithium electron configuration, we see that 1 electron exists in the last orbit of lithium.
Therefore, the valence electrons of lithium are 1. Finally, we can say that the valency and valence electrons of lithium are 1.
Determining the block of lithium by electron configuration
If the last electron enters the s-orbital after the electron configuration of the element, then that element is called the s-block element. We know lithium element electron configuration is 1s2 2s1. The electron configuration of lithium shows that the last electron of lithium enters the s-orbital.
Therefore, lithium is the s-block element. The elements in groups 1 and 2 are the s-block elements. And helium is the s-block element. There are 14 s-block elements in the 118 elements of the periodic table.
Lithium is an alkali metal
The elements in group-1 of the periodic table are alkali metals. Lithium is the element of group number 1 of the periodic table. Therefore, lithium is an alkali metal. (Excluding the only hydrogen)
Lithium ionic properties
When a charge-neutral atom leaves an electron and turns into a positive ion, it is called cation. Although the electron strength of the last orbit of an atom is higher, the force of attraction on that electron by the positive charge of the nucleus is less effective.
As the force of attraction is less effective, electrons are removed from the last orbit. And the atom turns into a cation. The last orbital of a lithium atom is converted into a cation by leaving an electron.
Li – e– → Li+
Lithium ion(Li+) electron configuration is 1s 2.
Oxidation and Reduction properties of lithium atoms
The element of group-1 is lithium. Which is an intense reducing element. The lithium atom donates 1 electron of the s-orbital. And the lithium atom forms the electron structure of the helium element.
The reducing intensity of lithium is so high that lithium atoms reduce the hydrogen to form lithium hydride compounds.
2Li + H2 → 2LiH
The ionization potential of the alkali metal decreases as it moves from top to bottom within the group of periodic tables. That is, the reduction capacity continues to increase.
As such, lithium is a weak reducing agent and cesium is a severe reducing agent. But lithium is the most powerful reducing agent among alkali metals. The oxidizing potential of lithium atoms is +3.04.
Properties of Lithium
- The atomic number of lithium is 3. The atomic number of an element is the number of electrons in that element. Therefore, the number of electrons in lithium is 3.
- Lithium standard atomic weight is 6.941.
- Lithium is an alkali and an intensely negative metal. Its oxides and hydroxides are strong alkalis.
- The value of electronegativity of lithium atoms is comparatively much lower. The value of electronegativity of lithium atoms is 0.98.
- The covalent radius of the lithium atom is 128 ± 7 pm.
- The ionic radius of the lithium atom is 6.0 × 10 –2 nm.
- Lithium atom van der Waals radius 182 pm.
- Ionization energies of lithium atoms E1 = 520 kj/mol, E 2 = 7298 kj/mol, E3 = 11815 kj/mol.
- The oxidation states of lithium atoms are +1.
- The volume of lithium atoms is 13.1cc / mol.
- The melting point of a lithium atom is 180.50 ° C (453.65 K, 356.90 ° F). And the boiling point is 1342 C.
- The period of the lithium element is 2. And the group is 1.
- The number of valency and valence electrons of a lithium atom is 1.
- Lithium forms both covalent and ionic bonds.
- Lithium is a highly electrically positive element. As a result, the lithium atom is stable and produces ions in the solution.
- 1 electron exists in the last orbit of lithium.
- The atomic radius of a lithium atom is 152 pm.
- Lithium atoms react with hydrogen, oxygen, and halogen to form compounds.
Ionic bonds of lithium
Lithium atoms form ionic bonds with fluorine atoms through the exchange of electrons.
The lithium electron configuration is 1s2 2s 1 and the electron configuration of fluorine atom is 1s2 2s2 2p5.
1 electron exists in the last orbit of the lithium atom. The lithium atom wants to be more stable by forming one helium atom by eliminating 1 electron in the last orbit. Again, 7 electrons exist in the last orbit of the fluorine atom.
The fluorine atom wants to be more stable like the neon atom by accepting 1 electron. The lithium atom donates one electron of its last orbit to the fluorine atom. And through ionic bonds, LiF forms compounds.
lithium reacts with other elements to form compounds
The reaction of lithium with halogen
Lithium atoms react with halogen to form halide compounds.
2Li + F2 → 2LiF
2Li + Cl2 → 2LiCl
2Li + Br2 → 2LiBr
2Li + I2 → 2LiI
The activity of alkali metals with specific halogens gradually increases from lithium to cesium. That is, Li < Na < K < Rb < Cs. But with the exception of lithium, all other alkali metal halides dissolve very easily in water.
The intense gravitational force between Li+ and F– ions in the crystal reduces the solubility of LiF. Therefore, LiF is less soluble in water. LiCl, LiBr, LiI are soluble in organic solvents ethanol and propanol.
The reaction of Oxygen with Lithium
Group-1 elements, such as alkali metals, have a greater ability to bind to oxygen. Lithium (an alkali metal) reacts with controlled amounts of oxygen to form LiO (oxide) compounds.
4Li (s) + O2 (g) → 2Li2O (lithium oxide)
Heating lithium with excess oxygen produces the compound Li2O2.
2Li + O2 → Li2O2 (lithium peroxide).
The reaction of lithium with hydrogen and the formation of compounds
Hydrogen electron configuration is 1s1. Alkali metals react with dry hydrogen at a temperature of about 400 ° C to form metallic hydrides. But the lithium atom is different from all other alkali metals. Lithium reacts with hydrogen at a temperature of 800 ° C to produce lithium hydride.
2Li + H2 → 2 LiH.
The reaction activity decreases as it moves from lithium to cesium element. Metal hydride stability tends to decrease from LiH to CsH.
Lithium reacts with water to produce LiOH.
2Li + 2H2O → 2LiOH + H2
Lithium (Li) is oxidized by oxygen in the air to produce alkaline Li2O.
4Li + O2 → 2Li2O
Li2O reacts with water to produce mild alkali LiOH.
Li2O + H2O → 2LiOH
As Li2O is alkaline, it destroys the acidity of HCl and produces salt and water.
Li2O + 2HCl → 2LiCl + H2O
The reaction of lithium with other elements
Lithium atoms react with sulfur and phosphorus to form sulfide and phosphide compounds.
16 Li + S8 → 8Li2S
12Li + P4 → 4Li3P
The alkali metal lithium reacts with nitrogen(N2) at high temperatures to form nitride compounds.
6Li + N2 → 2Li3N
The exceptional properties of lithium atoms
In general, elements of the same group have similarities in physical and chemical properties. The elements of group-1 are alkali metals. The elements are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs).
But the properties of lithium (Li) are different from the properties of all the other elements in this group. The elements in group-1 form ionic bonds in halide compounds. But the halide compounds of the lithium atom have covalent bonds.
For this reason, sodium halide is soluble in water but lithium halide is very slightly soluble in water. LiCl, LiBr, and LiI are soluble in various organic solvents (ethanol, propanol, ether).
Alkali metals react with hydrogen at 400 ° C to form hydride compounds. But lithium atoms form lithium hydride compounds with hydrogen at a temperature of 800 ° C.
2Li + H2 (800 ° C) → 2LiH.
The reasons for the exceptional properties of lithium (Li) are-
- Small size of Li atom and Li+ ion.
- The polarization capacity of Li+ ions is high.
- The zero d orbital is missing at the valence level.
- Lithium is a high ionic potential element.
Due to the exceptional properties of lithium (Li), several distinctions of lithium with other alkali metals have been observed. They are-
- Lithium is less active than alkali metals. Its bright color does not fade easily when it comes in contact with air. In the case of other alkali metals, their bright color fades in contact with air.
- Lithium (Li) reacts with oxygen to form only monoxide (Li2O) compounds. But never forms peroxide (Li2O2) or superoxide (LiO2).
- Lithium is the only alkali metal that reacts with nitrogen (N2) to produce Li3N.
6Li + N2 → 2Li3N.
All other alkali metals do not react with nitrogen (N2).
- When the alkaline metal nitride is heated, it decomposes and metallic nitride and oxygen are produced.
2MNO3 → 2 MNO2 + O2. Here, [M = Na, K, Rb]
- When lithium nitride is heated, it decomposes and produces lithium monoxide (Li2O), NO2 and oxygen (O2).
4LiNO3 (heat) → 2Li2O + 4NO2 + O2
- Hydroxides of alkali metals have a strong base. But lithium hydroxide is a weak base.
- Lithium chloride (LiCl) combines with water to form di-hydrate compounds. But NaCl, KCl, CsCl never form hydrate compounds.
The main topic of this article is the lithium electron configuration . Here, the method of the electron configuration of lithium atoms is discussed. Lithium electron configuration and orbital diagram are the main topics of this article.
Also, period and group determination, valence and valence electrons, various reactions and compound formation of lithium, bond formation of lithium have been discussed.
- How do you write the electron configuration for lithium?
Ans: Lithium electron configuration is 1s2 2s1.
- How many electrons are there in lithium?
Ans: 3 electrons.
- What are the three electrons of lithium?
- What is the atomic mass of lithium?
Ans: Lithium standard atomic mass is 6.941
- How many shells does lithium have?
Ans: 2 shells.
- How many valence electrons does lithium(Li) have?
Ans: The valence electron of lithium is one.