Bonds in Carbon Compounds

Ionic compounds have high melting and boiling points and conduct electricity in molten and dissolved states due to ionic bonds. In contrast, carbon compounds generally have lower melting and boiling points, as shown in the table below, indicating weaker intermolecular forces.

Most carbon compounds do not conduct electricity, which suggests they lack ionic bonds and do not produce ions in solution.

Electronic Configuration of Carbon

• Atomic number: 6
• Electronic configuration: 2,4
• Valence electrons: 4
• Nearest noble gases: Helium (2), Neon (2,8)

Since carbon has four valence electrons, it can bond in three possible ways to achieve stability:

1. Losing four electrons to form C⁴⁺

• This would require excessive energy, making it unstable.

2. Gaining four electrons to form C⁴⁻

• The carbon nucleus would struggle to hold ten electrons, making this unstable.

3. Sharing four electrons with other atoms (Preferred method)

• Carbon forms covalent bonds, where atoms share electrons instead of transferring them.

A covalent bond forms when atoms share electrons to complete their valence shells, making them stable without forming ions. The electron-dot structure represents these shared electrons.

Examples of Covalent Bonding:

1. Hydrogen (H₂)

• Each hydrogen atom has one electron and needs one more to be stable.
• Two hydrogen atoms share electrons, forming a single bond (H—H).

Electron dot structure and line structure of hydrogen molecule with a single bond

2. Oxygen (O₂)

• Each oxygen atom has six valence electrons and needs two more.
• Two oxygen atoms share two pairs of electrons, forming a double bond (O=O).

Double Bond

3. Nitrogen (N₂)

• Each nitrogen atom has five valence electrons and needs three more.
• Two nitrogen atoms share three pairs of electrons, forming a triple bond (N≡N).

Triple Bond

4. Methane (CH₄)

• Carbon needs four electrons to be stable.
• It shares one electron each with four hydrogen atoms, forming four single covalent bonds.
• Thus, covalent bonding allows carbon to form a wide variety of stable compounds.

Electron-dot structure and line structure of methane molecule

Models of methane molecule