Covalent Bonding in Carbon Where shared electrons craft the backbone of life.

What is a Covalent Bond?

Covalent Bond

A covalent bond forms when two atoms share one or more electron pairs, allowing each to achieve a stable outer shell.

Why Does Carbon Form Covalent Bonds?

1

Electronic Configuration 2,4

Carbon has four valence electrons in the 2s and 2p orbitals.

2

Energy Hurdle

Losing or gaining four electrons needs huge energy, so ionic routes are unfavourable.

3

Sharing for Stability

By sharing four electrons with other atoms, carbon completes its octet and forms covalent bonds.

Pro Tip:

Link carbon’s 2,4 configuration to its need to share—this is the key to understanding organic chemistry.

Single, Double & Triple Covalent Bonds of Carbon

Single Bond (C–H in CH4)

Shares 1 electron pair (2 e⁻) with another atom.
Only σ-bond present; free rotation possible.
Longest and weakest among the three bond types.

Double & Triple Bonds

Double: 2 shared pairs (1 σ + 1 π); C=C in C2H4.
Triple: 3 shared pairs (1 σ + 2 π); C≡C in C2H2.
Multiple bonds are shorter, stronger, and restrict rotation.

Key Similarities

All are covalent—electrons are shared, not transferred.
Each bond helps carbon achieve a stable octet.
Found widely in organic molecules and biomolecules.

Methane (CH₄): A Single-Bond Example

Electron-dot model and ball-and-stick model of CH₄

Electron-dot and ball-and-stick representations of CH₄

Electron-Dot and Structural Formula

Carbon shares one electron with each of four hydrogen atoms.

This sharing completes carbon’s octet and each hydrogen’s duet, illustrating covalent bonding.

Key Points:

  • Electron-dot formula: \( \mathbf{C} \) with four shared pairs, each pair between C and H.
  • Structural formula: \( \mathrm{H{-}C{-}H} \) shows four single covalent bonds.
  • Model highlights how methane achieves stable electronic configuration.

Ethene & Ethyne: Double and Triple Bonds

Electron-dot and structural models of ethene and ethyne side-by-side

Electron-dot & structural views of ethene and ethyne

How carbon forms multiple bonds

In ethene \(C_2H_4\), two shared electron pairs create a C=C double bond between the two carbons.

In ethyne \(C_2H_2\), three shared pairs form a C≡C triple bond, showing carbon can share six electrons.

Key Points:

  • Double bond = 4 shared electrons.
  • Triple bond = 6 shared electrons.
  • More shared pairs mean fewer hydrogens attach to carbon.

Properties of Covalent Compounds

Low melting & boiling points

Weak intermolecular forces let covalent compounds change state at small temperature rises.

Poor electrical conductors

No free ions or electrons, so current cannot pass through these compounds.

Insoluble in water

Non-polar molecules hardly mix with polar water but dissolve well in organic solvents.

Gases, liquids or soft solids

Weak forces keep particles loosely packed, giving covalent substances soft or volatile forms.

Build a Methane Molecule

Drag each hydrogen electron into the empty spots around carbon. Carbon must reach 8 electrons; each hydrogen needs 2.

Draggable Items

Hydrogen Electron 1
Hydrogen Electron 2
Hydrogen Electron 3
Hydrogen Electron 4

Drop Zones

Carbon Slot 1

Carbon Slot 2

Carbon Slot 3

Carbon Slot 4

Tip:

Carbon makes 4 shared pairs; place one pair with each hydrogen.

Multiple Choice Question

Question

Which statement best explains why carbon rarely forms C4+ or C4− ions?

1
Carbon’s nucleus is too small.
2
Too much energy is needed to lose or gain four electrons.
3
Carbon already possesses a stable octet.
4
Carbon has no valence electrons.

Hint:

Think about the energy required to remove or add four electrons to carbon’s outer shell.

Key Takeaways: Covalent Bonding in Carbon

Covalent bond: two atoms share one or more electron pairs.

Carbon (2,4) shares four electrons, creating four covalent bonds.

Single, double and triple bonds share 1, 2, 3 electron pairs respectively.

Methane, ethene and ethyne show single, double and triple bonds.

Covalent substances melt easily and seldom conduct electricity.

Minimalistic carbon atom icon with glowing shared-electron pairs

Thank You!

We hope you found this lesson informative and engaging.