Carbon is a group of 14th non-metal elements in the periodic table having an atomic mass of 12.011 u. Let us know some important properties of Carbon.
Carbon has an electronegativity of 2.55 and has higher ionization energy due to its 2s and 2p orbital which are closer to the nucleus. The electronegativity of C varies by its valency and the number of bonds it formed depends on the s character of the bond. The ionization of C depends on the covalent bond formation.
Carbon has two types of allotrope one is crystalline and the other is amorphous. In this article, we should learn the electronegativity property and ionization energy and comparison of electronegativity between Carbon and other elements in detail with proper explanation.
1. Does carbon have high electronegativity?
Carbon has high electronegativity and a value of 2.55 on the Pauling scale because –
- The lone pairs of carbon present in the s orbital which is closer to the nucleus.
- Carbon is placed 14th which is closer to groups 16th and 17th elements which are most electronegative in the periodic table
- Due to the smaller size of carbon, it can accumulate higher charge density in sigma electrons.
2. Hydrogen and carbon electronegativity
Carbon is slightly more electronegative than hydrogen which can be explained below –
| Electronegativity of Carbon | Electronegativity of Hydrogen | Reasons |
| 2.55 | 2.2 | A positive charge attracts a negative charge, so the higher the positive charge present over the nucleus higher will be the electronegativity. The positive charge present over C is higher than hydrogen, so C is more electronegative than H. |
Carbon and Hydrogen
3. Silicon and carbon electronegativity
Carbon is more electronegative than its higher congeners Silicon in the group 14th because –
| Electronegativity of Carbon | Electronegativity of Silicon | Reasons |
| 2.55 | 1.9 | Electronegativity decreased down the group of the periodic table because as we move down the group atomic size increases and effective nuclear charge decreases, and Si is present down the C, so it has a lower electronegativity than C. |
Carbon and Silicon
4. Nitrogen and carbon electronegativity
Now come to the comparison of electronegativity difference between Nitrogen and Carbon which is almost 0.5 because,
| Electronegativity of Carbon | Electronegativity of Nitrogen | Reasons |
| 2.55 | 3.04 | Carbon lies in group IVA, a less electronegative group among the non-metals in the periodic table, and the value is 2.55 whereas N belongs to group 15th element from the pnictogen family and present in the topmost position of that group having higher electronegativity. |
Carbon and Oxygen
5. Oxygen and carbon electronegativity
Now compare the electronegativity between Carbon and Oxygen in the following table,
| Electronegativity of Carbon | Electronegativity of Fluorine | Reasons |
| 2.55 | 3.44 | C lies in group 14 which is closer to the transition metal group but O lies in group VIA and is present in the top position also it is a chalcogen element so it has higher electronegativity, 3.44 as per the Pauling scale, and has high sigma electron affinity. |
Carbon and Oxygen
6. Carbon and fluorine electronegativity
Now compare the electronegativity between Carbon and the most electronegative fluorine in the following table,
| Electronegativity of Carbon | Electronegativity of Fluorine | Reasons |
| 2.55 | 3.98 | C is present in group 14th which is a non-metal group of moderate electronegativity but the electronegativity of F is almost 4 and it is the most electronegative element in the periodic table as per the Pauling scale as it is a halogen and present at top of group 17, so its electron affinity is very high. |
Carbon and Fluorine
7. Carbon and chlorine electronegativity
After F, chlorine is the 2nd most electronegative atom in the periodic table, and comparing its electronegativity with carbon,
| Electronegativity of Carbon | Electronegativity of Chlorine | Reasons |
| 2.55 | 3.16 | Down the group electronegativity decreases and for Cl it has a lower electronegativity than F as it is present down the F but it is present in the same group of the halogen family so it has a higher electronegativity than group 14th C. |
Carbon and Chlorine
8. Carbon and iodine electronegativity
Iodine has the least electronegative among the halogen elements and we have to compare its electronegativity with carbon.
| Electronegativity of Carbon | Electronegativity of Iodine | Reasons |
| 2.55 | 2.66 | The difference between electronegativity between C and I is almost .11 which is very less because I is the least electronegative among halogen atoms and has lower sigma electron density whereas C has almost the same electronegativity. |
Carbon and Chlorine
9. Iron and carbon electronegativity
Iron has an electronegativity of 1.83 as it is a transition metal atom and compare its electronegativity with carbon in the following table,
| Electronegativity of Carbon | Electronegativity of Iron | Reasons |
| 2.55 | 1.83 | Iron is less electronegative than C because Fe is a transition metal and forms metal it is showing electropositive character and easily loose electrons but c is a non-metal so it has a higher electronegativity than Fe. |
Carbon and Iron
10. Carbon ionization energy
Carbon shows up to the sixth ionization by removing all the valence electrons from its shell by respective orbital as its electronic configuration still be [He]2s22p4, we will discuss it in the following section –
- 1st ionization energy – the first ionization energy for C is 1086.5 KJ/mol which occurs from its 2p orbital.
- 2nd Ionization energy – the 2nd ionization occurs from 2p orbital and the value is 2427.1 KJ/mol as it is removed from +1 excited state so required higher energy.
- 3rd Ionization energy – The third electron was removed from the 2s orbital of C and required higher energy, 4620.5 KJ/mol because C has a higher electronegativity.
- 4th ionization energy – The fourth electron was removed from the 2s orbital also and it is closer to the nucleus, so it required a larger amount of energy 6222.7 KJ/mol because it occurs from a +3 excited state.
Carbon dioxide ionization energy
The ionization energy for CO2 is 541.085 eV because the electron is removed from the highest occupied molecular orbital of carbon dioxide which is the oxygen site and has a higher electronegativity.
Carbon monoxide ionization energy
The ionization energy of CO is 296 eV because the electron is removed from the HOMO of CO which is the C site and has less s character so a lesser amount of energy will be required.
11. Carbon ionization energy graph
Carbon’s 1st, 2nd, and 3rd ionization energy from its respective orbital is shown below graph –
Ionization Energies of Carbon
Conclusion
C is the group’s 14th top-most non-metal element, so it has a higher electronegativity than its other higher congeners. When the C molecule undergoes bond formation then its electronegativity will be changed. Triple bonded C is the most electronegative followed by double bonded and then single bonded, and the reason for its hybridization value and higher s character.
Read more about Boron Electronegativity & Ionization Energy, Argon Electronegativity & Ionization Energy and Chlorine Electronegativity & Ionization Energy.
Hi……I am Biswarup Chandra Dey, I have completed my Master’s in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.