Question

Carbon shows catenation while silicon shows little because (1) Silicon is a metalloid and carbon is a nonmetal. (2) Silicon forms ionic compounds, whereas carbon forms covalent compounds. (3) The Si Si bond is stronger than \(\mathrm{C} \mathrm{C}\) bond. (4) The C C bond is stronger than Si Si bond.

Short answer

The C-C bond is stronger than the Si-Si bond.

Step-by-step solution

Identify the property of C and Si bonds

Examine the nature of the bonds between carbon atoms and silicon atoms. The strength of the bond will influence catenation ability.

Compare the bond strengths

The C-C bond strength is stronger in comparison to the Si-Si bond strength. A stronger bond implies more stability and a greater likelihood of forming long chains.

Infer the reason for catenation

Due to the stronger C-C bond, carbon can form long chains more effectively (catenation) than silicon, whose weaker Si-Si bonds make catenation less favorable.

Match the inference with options

Option 4 states that the C-C bond is stronger than the Si-Si bond, which aligns with the explanation regarding catenation.

Conclude the answer

The correct answer is that carbon shows more catenation than silicon because the C-C bond is stronger than the Si-Si bond.

Key concepts

C-C bond strength

Carbon has an exceptional ability to form strong bonds with itself, creating long and stable chains. This property is central to the chemistry of organic compounds and is known as catenation. The strength of the carbon-carbon (C-C) bond is one of the key reasons behind this capacity. The bond energy of a typical C-C bond is about 348 kJ/mol. This high bond energy signifies that a lot of energy is needed to break the bond, thus making it stable and durable.

The stability and strength of the C-C bond allow carbon atoms to link together in various lengths and structures, such as chains, rings, and networks. These structures form the backbone of countless organic molecules, ranging from simple hydrocarbons to complex biomolecules like DNA and proteins. The ability to form such diverse structures is essential for the complexity and functionality of organic life.

In summary, the high bond energy of the C-C bond underpins the extensive catenation ability of carbon, leading to the formation of myriad organic compounds.

Si-Si bond strength

Silicon, although similar to carbon in many respects, shows significantly less catenation. This is largely due to the weaker bond between silicon atoms (Si-Si). The bond energy of the Si-Si bond is approximately 226 kJ/mol, considerably lower than that of the C-C bond.

The lower bond energy means that Si-Si bonds are less stable and easier to break. This reduced stability limits silicon's ability to form long, stable chains or networks similar to those formed by carbon. For this reason, silicon-based compounds often show simpler and less diverse structures.

Despite this limitation, silicon is still a crucial element, particularly in the fields of electronics and materials science. For example, silicones, which contain Si-O-Si linkages instead of Si-Si bonds, are used to create polymers with useful properties such as flexibility and heat resistance. Nevertheless, the inherent weakness of the Si-Si bond prevents silicon from exhibiting the same level of catenation as carbon.

Bond stability

Bond stability is a critical factor in determining the properties and behaviors of elements and their compounds. Bond stability is primarily influenced by bond energy, which refers to the amount of energy required to break a bond.

Higher bond energy generally means a more stable bond, as it takes more effort to break it. For instance, the C-C bond is much more stable than the Si-Si bond due to its higher bond energy. This stability leads to the formation of stable and diverse carbon-based structures.

In contrast, the lower bond energy of the Si-Si bond bespeaks lower stability, making it more susceptible to breaking under normal conditions. This reduced stability is why silicon cannot form extensive and diverse structures akin to carbon.

The concept of bond stability also explains the larger breadth of organic chemistry compared to silicon chemistry. While both carbon and silicon can form four bonds with other atoms, the unparalleled stability of C-C bonds allows for the rich variety of organic molecules essential for life. Silicon, in comparison, forms stronger bonds with oxygen (Si-O), leading to a distinct set of silicon-based materials, such as silicates and silicones.