Question

Explain each statement in terms of atomic properties: (a) Carbon engages in covalent rather than ionic bonding. (b) Carbon has four bonds in all its organic compounds. (c) Carbon forms neither stable cations, like many metals, nor stable anions, like many nonmetals. (d) Carbon atoms bond to other carbon atoms more extensively than do the atoms of any other element. (e) Carbon forms stable multiple bonds.

Short answer

Carbon forms covalent bonds because it needs four electrons to complete its octet. It bonds four times in organic compounds and doesn't form stable ions due to high energy demands. Carbon binds well with other carbons and forms stable multiple bonds due to effective p-orbital overlap.

Step-by-step solution

Explaining Covalent Bonding of Carbon

Carbon has 4 valence electrons and requires 4 more to achieve a full octet. Instead of losing or gaining electrons, carbon shares its electrons with other atoms, resulting in covalent bonds, which allows for stable molecule formation.

Understanding Carbon's Four Bonds

Carbon forms four bonds in its organic compounds because it has four valence electrons and it needs four more to complete its octet. This leads to four shared pairs of electrons with other atoms, ensuring its stability.

Carbon's Inability to Form Stable Ions

Carbon does not typically form stable cations or anions due to the high energy required to either lose or gain four electrons. Losing four electrons to form a cation or gaining four electrons to form an anion would make the atom highly unstable.

Bonding Between Carbon Atoms

Carbon atoms bond with other carbon atoms extensively because of the similar size and similar electronegativity, which allows them to form strong covalent bonds.

Stability of Carbon's Multiple Bonds

Carbon can form stable multiple bonds (double and triple bonds) due to the effective overlap of p-orbitals. This overlapping creates pi bonds which, along with sigma bonds, contribute to the bond's stability.

Key concepts

Covalent Bonding

Carbon primarily engages in covalent bonding because of its electron configuration. It has 4 valence electrons on its outer shell, but it needs 8 electrons to fulfill the octet rule and become stable. Rather than gaining or losing electrons, which would require a significant amount of energy, carbon shares its electrons with other atoms.
This sharing of electrons leads to the formation of covalent bonds, which are both strong and stable. This is why carbon-based molecules form the backbone of organic chemistry.

Carbon Valence Electrons

Carbon has four valence electrons, which are the electrons available for bonding. These four electrons play a crucial role in the molecule's stability.
Since carbon needs four more electrons to satisfy the octet rule, it can form up to four covalent bonds with other atoms. This ability makes it incredibly versatile and capable of forming a wide variety of complex molecules, including those essential to life.

Octet Rule

The octet rule is a chemical principle that states atoms are most stable when their outermost electron shell contains eight electrons. For carbon, this means it must pick up four additional electrons.
To comply with this rule, carbon shares its four valence electrons with other atoms through covalent bonding. This results in a full outer shell, fulfilling the octet rule, and stabilizing the molecule.

Cation and Anion Stability

Carbon struggles to form stable ions due to the energy demands involved. Losing four electrons to become a cation or gaining four electrons to become an anion requires a significant amount of energy, making carbon ions highly unstable.
This instability is why carbon prefers covalent bonding, as sharing electrons is energetically favorable and results in more stable compounds.

Catenation

Catenation is the ability of an element to bond to itself, forming long chains or structures. Carbon excels at this due to its unique bonding properties.
The carbon-carbon bond is stable and strong, allowing for long chains and complex structures. This characteristic is particularly important in organic chemistry, where carbon chains form the backbone of most organic molecules.

Pi Bonds

Pi bonds form when the p-orbitals of two atoms overlap side-by-side. In molecules with double or triple bonds, pi bonds are present along with sigma bonds.
These pi bonds contribute to the molecule's rigidity and stability. In carbon atoms, effective overlap of p-orbitals leads to strong pi bonds, making multiple bonds possible. This allows for a variety of stable structures, such as alkenes and alkynes.

Sigma Bonds

Sigma bonds are the strongest type of covalent bond and form when two atomic orbitals overlap along the axis connecting the two bonding nuclei. They are present in all single bonds.
In carbon compounds, sigma bonds form the backbone of the molecule. Each carbon atom can form up to four sigma bonds with other atoms, which gives rise to a plethora of complex and stable molecular structures.