Carbon Electron Configuration and Atomic Orbital Diagram

Carbon is the 6th element in the periodic table and the symbol is ‘C’. Carbon has an atomic number of 6, which means that its atom has six electrons around its nucleus. To write the electron configuration for carbon, the first two electrons enter the 1s orbital. Since the 1s orbital can hold only two electrons the next two electrons enter the 2s orbital. The remaining two electrons enter the 2p subshell. Therefore, the electron configuration of carbon will be 1s² 2s² 2p².

The electron configuration of carbon refers to the arrangement of electrons in the carbon 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 carbon electron configuration, you need to 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 carbon electron configuration. I hope this will be helpful in your study.

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Electron arrangement for Carbon Atom through Bohr Model

The atomic number is the number of electrons in that element. The atomic number of carbon is 6. That is, the number of electrons in carbon is 6. Therefore, a carbon atom will have two electrons in the first shell and four in the 2nd shell. Therefore, the order of the number of electrons in each shell of the carbon(C) atom is 2, 4.

Electron configuration of carbon 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 carbon should be written as 1s² 2s² 2p².

Note: The unabbreviated electron configuration of carbon is [He] 2s² 2p². When writing an electron configuration, you have to write serially.

How to draw the orbital diagram of carbon

The orbital diagram of carbon is a graphical representation of the electron configuration of carbon atom. This diagram shows how the electrons in the carbon atom are arranged in different orbitals and indicates the spin of electrons. Orbital is the region of space around the nucleus of an atom where electrons are found.

To draw an orbital diagram of any atom, you first need to know the atomic orbitals and the orbital notation for that atom, which is already discussed above. Also, you need to know Hund’s and Paul’s exclusion principle. These two fundamental principles explain how these electrons occupy the 1s, 2s, and 2p orbitals. Below, we define each principle and apply it to carbon, helping students understand its atomic structure and versatile bonding behavior.

Hund’s Rule

Hund’s Rule states that when electrons fill orbitals of the same energy (degenerate orbitals, like the three 2p orbitals: 2p_x, 2p_y, 2p_z), they occupy each orbital singly with parallel spins (e.g., all ↑) before pairing up. This arrangement minimizes electron-electron repulsion and maximizes stability.

Pauli Exclusion Principle

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum numbers. This means each orbital can hold up to two electrons, and they must have opposite spins (e.g., one ↑ and one ↓).

Draw the orbital diagram of carbon

Orbital diagrams are usually represented by boxes. Each box represents an orbital and the arrows within the box represent the position of the electron. The boxes are arranged in order of energy of the orbitals. The lowest energy orbitals are closest to the nucleus and the higher energy orbitals are progressively further away from the nucleus in order of their energy levels.

To write the orbital diagram of carbon, the 1s orbital is the closest and lowest energy orbital to the nucleus. Therefore, the electrons will first enter the 1s orbital. According to Hund’s principle, the first electron will enter the 1s orbital in the clockwise direction and the second one will enter the 1s orbital in the anti-clockwise direction.

The 1s orbital is now filled with two electrons. Then the next two electrons will enter the 2s orbital just like the 1s orbital. The 2s orbital is now full. So the remaining two electrons will enter the 2p (p_x, p_y) orbital one by one in a clockwise direction. This is clearly shown in the figure of the orbital diagram of carbon.

Why This Matters for Carbon

Electron configuration of carbon in the excited state

Atoms can jump from one orbital to another in an excited state is called a quantum jump. The ground state electron configuration of carbon is 1s² 2s² 2p². We already know that the p-subshell has three orbitals. The orbitals are p_x, p_y, and p_z and each orbital can have a maximum of two electrons.

In the carbon ground-state electron configuration, the two electrons of the 2p orbital are located in the p_x, p_y orbitals, and the spin of the two electrons is the same. Then the correct electron configuration of carbon in the ground state will be 1s² 2s² 2p_x¹ 2p_y¹. Here, carbon has two unpaired electrons. Therefore, the valency of carbon is 2.

Also, the valency of an element is determined by electron configuration in the excited state. When the carbon atom is excited, then the carbon atom absorbs energy. As a result, an electron in the 2s orbital jumps to the 2p_z orbital. Therefore, the electron configuration of carbon(C*) in an excited state will be 1s² 2s¹ 2p_x¹ 2p_y¹ 2p_z¹. Here, carbon has four unpaired electrons. In this case, the valency of carbon is 4.

Carbide ion(C⁴⁻) electron configuration

The electron configuration shows that the last shell of carbon has four electrons. Therefore, the valence electrons of carbon are four. The element that receives electrons and forms a bond is called anion.

During the formation of a bond, the last shell of carbon receives four electrons and turns into a carbide ion(C⁴⁻). That is, carbon is an anion element.

C + 4e^– → C^4–

Here, the electron configuration of carbide ion(C⁴⁻) is 1s² 2s² 2p⁶. This electron configuration shows that the carbide ion(C⁴⁻) acquired the electron configuration of neon and it achieves a stable electron configuration. Carbon exhibits a +4, +2, and -4 oxidation state. The oxidation state of the element changes depending on the bond formation.

How to determine the group and period of carbon through the electron configuration?

The last orbit of an element is the period of that element. The electron configuration of the carbon atom shows that the last orbit of the carbon atom is 2. So, the period of carbon 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. But in the case of p-block elements, group diagnosis is different.

To determine the group of p-block elements, the group has to be determined by adding 10 to the total number of electrons in the last orbit. The total number of electrons in the last orbit of the carbon(C) atom is four. That is, the group number of carbon is 4 + 10 = 14. Therefore, we can say that the period of the carbon element is 2 and the group is 14.

How to determine the block of carbon through the electron configuration?

The elements in the periodic table are divided into four blocks based on the electron configuration of the element. The block of elements is determined based on the electron configuration of the element.

If the last electron enters the p-orbital after the electron configuration of the element, then that element is called the p-block element. The electron configuration shows that the last electron of carbon enters the p-orbital. Therefore, carbon is the p-block element.

Activation sequence of carbon atom

The elements of group 14 are relatively less active. However, the activity of the element increases as it moves from the top to the bottom of the group.

Carbon is the first element of group 14. Carbon is the number one element in group 14. For this, the activation of carbon atoms is very low.

Reaction structure of carbon atom

The carbon atom reacts with the oxygen atom to form oxide compounds.

C + O₂ → CO

C + O₂ → CO₂

In general, the oxides of elements with higher oxidation values are more acidic than the oxides of elements with lower oxidation values. CO is a neutral oxide, but CO₂ is an acidic oxide.

CO₂ + 2NaOH → Na₂CO₃ + H₂O

CO₂ behaves like an acidic oxide.

2C + O₂ → 2CO

Here, CO reveals the behavior of the neutral oxide.

The element carbon of group-14 reacts with water to produce [CO + H₂] water gas.

C + H₂O (1300 C) → [CO + H₂]

Carbon atoms react with halogen to form tetrahalide compounds.

• C + 2F₂ → CF4
• C + 2Cl₂ → CCl₄
• C + 2Br₂→ CBr₄
• C + 2I₂ → CI₄

The carbon atom reacts with hydrogen to produce methane gas.

C + 2H₂ → CH₄

Humid analysis of carbon halide

The halide compounds of the 14th group elements, especially the humid analyzed chloride, are of a slightly different nature. In the case of humid analysis, the empty d-orbital of the atom plays a major role.

The second period and 14-group element is carbon. No d-orbital is present at the valence level of the carbon atom. Therefore, CCl₄ is not humid analyzed.

Exceptional properties of carbon

The first element of the 14-group is carbon. The 14-group exhibits the exception of carbon from other elements. The exceptions to carbon are shown below-

• The ionic size of carbon atoms is unusually small.
• The electronegativity of carbon atoms is high.
• Carbon is a high ionic potential element.
• The d-orbital is missing in the valence chamber.
• Carbon variant diamonds are very hard.
• The melting point and boiling point of carbon atoms are higher than other elements.
• The valence level of a carbon atom has 2 s-orbitals and 2 p-orbitals. When active, the s-orbital has 1 and the p-orbital has 3 electrons. The maximum valence(valency) of carbon is 4. Since the other elements in the group have d-orbitals present, they can extend the valence up to 6. For example, in the case of silicon (SiF₆)^2– but [CF₆)^2– is not possible.
• Small size and high electrical negative element. For this, carbon atoms form single bonds, double bonds, and tri-bonds with other atoms and other elements.
• Catenation; This is one of the characteristics of carbon atoms. Carbon atoms join together to form long chains and rings. Such religions are created because of the small size of the carbon atom and the high carbon-carbon bonding strength. Carbon-carbon bonding strength 348kj/mol.

The bonding structure of carbon

Carbon tetrachloride(CCl₄) bonding Structure

There are four electrons in the last orbit of a carbon atom. The carbon atom wants to stabilize by taking four more electrons in its last orbit. Again, the electron configuration of chlorine atom shows that the last shell of the chlorine atom has seven electrons.

The chlorine atom wants to complete an octave by taking in an electron. Therefore, a carbon atom forms a carbon tetrachloride(CCl₄) compound through covalent bonds by sharing electrons with four chlorine atoms.

Methane(CH₄) bond formation

The above electron configuration shows that there are four electrons in the last orbit of the carbon atom. Carbon wants to be stable by taking four electrons in its last orbit(shell).

Again, the hydrogen atom wants to be as stable as helium by taking an electron and completing its first orbit. Therefore, a carbon atom shares electrons with four hydrogen atoms to form the methane(CH₄)compound through covalent bonding.

Properties of carbon atom

• The atomic number of carbon atoms is 6. The atomic number of an element is the number of electrons and protons in that element. That is, the number of electrons and protons in the carbon atom is six.
• The active atomic mass of the carbon atom is [12.0096, 12.0116].
• Carbon is non-metal.
• The valency of a carbon atom is 2, 4 and the valence electrons of a carbon atom are four.
• Carbon atoms are the 2nd period of the periodic table and an element of the 14-group.
• Carbon is an electrically negative element.
• Carbon is an anion element.
• Carbon atoms form covalent bonds.
• Carbon is the p-block element. The ionic energy value of carbon atoms is higher than that of s-block elements.
• Carbon is thermally conductive and electricity is slightly conductive.
• The melting point of a carbon atom is 3550°C and the boiling point is 4827°C.
• The electronegativity of carbon atoms is 2.55 (Pauling scale).
• The oxidation states of carbon are -4, 2, and 4.
• The atomic radius of a carbon atom is 67 pm.
• The carbon atom van der Waals radius is 170 pm
• Ionization energies of carbon atoms are 1st: 1086.5 kJ/mol, 2nd: 2352.6 kJ/mol, and 3rd: 4620.5 kJ/mol.
• The electron addiction of carbon atoms is –153.9 kJ mol^–1
• The covalent radius of the carbon atom is sp3: 77 pm, sp2: 73 pm, sp: 69 pm.
• C = O Bond Length 123 pm, C – O Bond Length 143 pm, C – C Bond Length 154pm, C = C Bond Length 133 pm, C – H (Alken) Bond Length 109pm, C – H (Alkyne) Bond Length 108 pm, C – H (alkyne) 105 pm, C = N bond length 138pm.

References

1. Fink, J. T. J. A. P., Müller-Heinzerling, T., Pflüger, J., Bubenzer, A., Koidl, P., & Crecelius, G. (1983). Structure and bonding of hydrocarbon plasma generated carbon films: an electron energy loss study. Solid state communications, 47(9), 687-691.
2. Liang, C., & Schaefer, H. F. (1990). Carbon clusters: The structure of C1 studied with configuration interaction methods. The Journal of chemical physics, 93(12), 8844-8849.