Tellurium Electron Configuration and Te²⁻, Te⁴⁺ Ions
Tellurium is the 52th element in the periodic table and the symbol is ‘Te’. Tellurium has an atomic number of 52, which means that its atom has 52 electrons around its nucleus.
The electron configuration of tellurium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p4, which means that the first two electrons enter the 1s orbital. Since the 1s orbital can hold only two electrons, the next two will enter the 2s orbital. The next six electrons enter the 2p subshell. The p subshell can hold a maximum of six electrons. So first we put six electrons in the 2p subshell and then the next two electrons in the 3s orbital.
Since the 3s is now full, the electrons will move to the 3p subshell, where the next six electrons will enter. The 3p subshell is now full. Consequently, the following two electrons will enter the 4s orbital. Since the 4s orbital is full, the next ten electrons will move into the 3d subshell. The d subshell can hold a maximum of ten electrons. So, the next six electrons will enter the 4p subshell.
Since the 4p is full, the next two electrons will move to the 5s orbital. The 5s orbital is now full. Consequently, the next ten electrons will enter the 4d subshell. Since the 4d is full, the remaining four electrons will enter the 5p subshell. Hence, the electron configuration of tellurium will be 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p4.
The electron configuration of tellurium refers to the arrangement of electrons in the tellurium atom’s orbitals. It describes how electrons are distributed among the various atomic orbitals and energy levels, and provides a detailed map of where each electron is likely to be found.
To understand the mechanism of tellurium electron configuration, you must understand two basic things. These are orbits and orbitals. Also, you can arrange electrons in those two ways. In this article, I have discussed all the necessary points to understand the mechanism of tellurium electron configuration. I hope this will be helpful in your study.
Electron arrangement of Tellurium through the Bohr model

Scientist Niels Bohr was the first to give an idea of the atom’s orbit. He provided a model of the atom in 1913 and provided a complete idea of orbit in that model.
The electrons of the atom revolve around the nucleus in a certain circular path. These circular paths are called orbits (shells or energy levels). These orbits are expressed by n. [n = 1,2,3,4 . . . The serial number of the orbit]
The name of the first orbit is K, L is the second, M is the third, and N is the name of the fourth orbit. The electron holding capacity of each orbit is 2n2.
| Shell Number (n) | Shell Name | Electrons Holding Capacity (2n2) |
| 1 | K | 2 |
| 2 | L | 8 |
| 3 | M | 18 |
| 4 | N | 32 |
Explanation:
- Let, n = 1 for K orbit. So, the maximum electron holding capacity in the K orbit is 2n2 = 2 × 12 = 2 electrons.
- n = 2, for L orbit. The maximum electron holding capacity in the L orbit is 2n2 = 2 × 22 = 8 electrons.
- n=3 for M orbit. The maximum electron holding capacity in the M orbit is 2n2 = 2 × 32 = 18 electrons.
- n=4 for N orbit. The maximum electron holding capacity in N orbit is 2n2 = 2 × 42 = 32 electrons.
Therefore, the maximum electron holding capacity in the first shell is two, the second shell is eight and the 3rd shell can have a maximum of eighteen electrons.
The atomic number is the number of electrons in that element. The atomic number of tellurium is 52. That is, the number of electrons in tellurium is fifty-two. Therefore, a tellurium atom will have two electrons in the first shell, eight in the 2nd orbit, and eighteen electrons in the 3rd shell.
According to Bohr’s formula, the fourth shell will have twenty-four electrons but the fourth shell of tellurium will have eighteen electrons and the remaining six electrons will be in the fifth shell. Therefore, the order of the number of electrons in each shell of the tellurium atom is 2, 8, 18, 18, 6.
The Bohr atomic model has many limitations. In the Bohr atomic model, the electrons can only be arranged in different shells but the exact position, orbital shape, and spin of the electron cannot be determined.
Also, electrons can be arranged correctly from 1 to 18 elements. The electron arrangement of any element with atomic number greater than 18 cannot be accurately determined by the Bohr atomic model following the 2n2 formula. We can overcome all limitations of the Bohr model following the electron configuration through orbital.
Electron configuration of Tellurium through orbital
Atomic energy shells are subdivided into sub-energy levels. These sub-energy levels are also called orbital. The most probable region of electron rotation around the nucleus is called the orbital.
The sub-energy levels depend on the azimuthal quantum number. It is expressed by ‘l’. The value of ‘l’ is from 0 to (n – 1). The sub-energy levels are known as s, p, d, and f.
| Orbit Number | Value of ‘l’ | Number of subshells | Number of orbitals | Subshell name | Electrons holding capacity | Electron configuration |
| 1 | 0 | 1 | 1 | 1s | 2 | 1s2 |
| 2 | 0 1 | 2 | 1 3 | 2s 2p | 2 6 | 2s2 2p6 |
| 3 | 0 1 2 | 3 | 1 3 5 | 3s 3p 3d | 2 6 10 | 3s2 3p6 3d10 |
| 4 | 0 1 2 3 | 4 | 1 3 5 7 | 4s 4p 4d 4f | 2 6 10 14 | 4s2 4p6 4d10 4f14 |
Explanation:
- If n = 1,
(n – 1) = (1–1) = 0
Therefore, the value of ‘l’ is 0. So, the sub-energy level is 1s. - If n = 2,
(n – 1) = (2–1) = 1.
Therefore, the value of ‘l’ is 0, 1. So, the sub-energy levels are 2s, and 2p. - If n = 3,
(n – 1) = (3–1) = 2.
Therefore, the value of ‘l’ is 0, 1, 2. So, the sub-energy levels are 3s, 3p, and 3d. - If n = 4,
(n – 1) = (4–1) = 3
Therefore, the value of ‘l’ is 0, 1, 2, 3. So, the sub-energy levels are 4s, 4p, 4d, and 4f. - If n = 5,
(n – 1) = (n – 5) = 4.
Therefore, l = 0,1,2,3,4. The number of sub-shells will be 5 but 4s, 4p, 4d, and 4f in these four subshells it is possible to arrange the electrons of all the elements of the periodic table.
| Sub-shell name | Name source | Value of ‘l’ | Value of ‘m’ (0 to ± l) | Number of orbital (2l+1) | Electrons holding capacity 2(2l+1) |
| s | Sharp | 0 | 0 | 1 | 2 |
| p | Principal | 1 | −1, 0, +1 | 3 | 6 |
| d | Diffuse | 2 | −2, −1, 0, +1, +2 | 5 | 10 |
| f | Fundamental | 3 | −3, −2, −1, 0, +1, +2, +3 | 7 | 14 |
The orbital number of the s-subshell is one, three in the p-subshell, five in the d-subshell, and seven in the f-subshell. Each orbital can have a maximum of two electrons.
The sub-energy level ‘s’ can hold a maximum of two electrons, ‘p’ can hold a maximum of six electrons, ‘d’ can hold a maximum of ten electrons, and ‘f’ can hold a maximum of fourteen electrons.
Aufbau is a German word, which means building up. The main proponents of this principle are scientists Niels Bohr and Pauli. The Aufbau method is to do electron configuration through the sub-energy level.
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.

The energy of an orbital is calculated from the value of the principal quantum number ‘n’ and the azimuthal quantum number ‘l’. The orbital for which the value of (n + l) is lower is the low energy orbital and the electron will enter that orbital first.
| Orbital | Orbit (n) | Azimuthal quantum number (l) | Orbital energy (n + l) |
| 3d | 3 | 2 | 5 |
| 4s | 4 | 0 | 4 |
Here, the energy of 4s orbital is less than that of 3d. So, the electron will enter the 4s orbital first and enter the 3d orbital when the 4s orbital is full. Following the Aufbau principle, the sequence of entry of electrons into orbitals is 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p.
Therefore, the complete electron configuration for tellurium should be written as 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p4.
Note: The unabbreviated electron configuration of tellurium is [Kr] 4d10 5s2 5p4. When writing an electron configuration, you have to write serially.

The excited state electron configuration of Tellurium
Atoms can jump from one orbital to another orbital in an excited state. This is called quantum jump. The ground-state electron configuration of tellurium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p4. In the tellurium ground-state electron configuration, the last electrons of the 5p orbital are located in the 5px(2), 5py and 5pz orbitals.
We already know that the p-subshell has three orbitals. The orbitals are px, py, and pz and each orbital can have a maximum of two electrons. Then the correct electron configuration of tellurium in the ground state will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5px2 5py1 5pz1. This electron configuration shows that the last shell of the tellurium atom has two unpaired electrons. So in this case, the valency of tellurium is 2.
When the tellurium atom is excited, then the tellurium atom absorbs energy. As a result, an electron in the 5px orbital jumps to the 5dxy orbital. We already know that the d-subshell has five orbitals. The orbitals are dxy, dyz, dzx, dx2-y2 and dz2 and each orbital can have a maximum of two electrons. Therefore, the electron configuration of tellurium(Te*) in an excited state will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5px1 5py1 5pz1 5dxy1.
The valency of the element is determined by electron configuration in the excited state. Here, tellurium has four unpaired electrons. In this case, the valency of tellurium is 4.
When tellurium is further excited, then an electron in the 5s orbital jumps to the 5dyz orbital. Therefore, the electron configuration of tellurium(Te**) in an excited state will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1 5px1 5py1 5pz1 5dxy1 5dyz1. This electron configuration shows that the last shell of the tellurium atom has six unpaired electrons. So in this case, the valency of tellurium is 6. From the above information, we can say that tellurium exhibits variable valency.
Tellurium ion(Te2-,Te4+,Te6+) electron configuration
After arranging the electrons, it is seen that the last shell of the tellurium atom has six electrons. Therefore, the valence electrons of tellurium are six. The elements that have 5, 6, or 7 electrons in the last shell receive the electrons in the last shell during bond formation.
The elements that receive electrons and form bonds are called anions. During the formation of bonds, the last shell of tellurium receives two electrons and turns into a telluride ion(Te2-). Therefore, tellurium is an anion element.
Te + 2e− ↔ Te2−
Here, the electron configuration of telluride ion(Te2-) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6. This electron configuration shows that the telluride ion(Te2-) has five shells and the 5th shell has eight electrons.
The electron configuration shows that the telluride ion(Te2-) has acquired the electron configuration of xenon and it achieves a stable electron configuration. Tellurium is a classified metalloid element. Therefore, tellurium is a also cation element.
The element that forms a bond by donating electrons is called cation. The tellurium atom donates four electrons in the 5p orbital to form a tellurium ion(Te4+).
Te – 4 e− ↔ Te4+
Here, the electron configuration of the tellurium ion(Te4+) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2. On the other hand, the tellurium atom donates four electrons in the 5p orbital and two electrons in the 5s orbital to convert the tellurium ion(Te6+).
Te – 6 e− ↔ Te6+
Here, the electron configuration of tellurium ion(Te6+) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10. This electron configuration shows that the tellurium ion(Te6+) has four shells and the last shell has eighteen electrons and it achieves a stable electron configuration. Tellurium atom exhibits -2, +2, +4, +6 oxidation states. The oxidation state of the element changes depending on the bond formation.
