Question

The interlayer distance in graphite is (1) very small, the laycrs being tightly packed (2) many times largcr than the covalent radius of carbon (3) about four times more than the covalent radius of carbon (4) the same as the covalent radius of carbon

Short answer

(3) about four times more than the covalent radius of carbon

Step-by-step solution

Understand the Question

The question asks about the characteristic of the interlayer distance in graphite in relation to the covalent radius of carbon. There are four options provided, and the goal is to identify the correct one.

Review Key Concepts

Recall that graphite has a layered structure where each layer consists of carbon atoms arranged in a hexagonal lattice. The interlayer distance refers to the separation between these layers.

Covalent Radius of Carbon

The covalent radius of carbon is approximately 0.077 nm (or 0.77 Å). This value helps in evaluating the different options provided.

Examine the Options

Compare the interlayer distance in graphite to the covalent radius of carbon: 1. Very small, layers tightly packed: This implies a much smaller separation, which conflicts with known data.2. Many times larger: This is vague but essential to consider.3. About four times more: This suggests a specific multiplication factor.4. The same: This is incorrect as the layers in graphite are not as closely packed.

Correct Comparison

The actual interlayer distance in graphite is approximately 0.335 nm (or 3.35 Å). Comparing this to the covalent radius of carbon (0.077 nm), it is evident that the interlayer distance is roughly four times the covalent radius.

Conclusion

Given the comparison, the closest and most accurate option is (3) about four times more than the covalent radius of carbon.

Key concepts

covalent radius of carbon

The covalent radius is a measure of the size of an atom that forms part of a single covalent bond. Specifically for carbon, this radius is quite small, approximately 0.077 nm (or 0.77 Å). This tiny distance highlights how closely atoms are packed when they share electrons in a covalent bond. Understanding the covalent radius helps in comprehending various structural properties of materials, such as the interlayer distance in graphite.

When comparing measurements like the interlayer distance in graphite, knowing that the covalent radius directly influences these distances is crucial.

graphite structure

Graphite is a unique form of carbon known for its layered structure. Each layer is composed of carbon atoms arranged in a hexagonal lattice. Within each layer, the carbon atoms are covalently bonded, creating strong in-plane bonds. However, the layers themselves are held together much more loosely. These interlayer bonds are known as Van der Waals forces, which are significantly weaker than the covalent bonds within each layer.

This structural difference explains many of graphite's properties, including its electrical conductivity and softness. Because of the weak interlayer forces, these layers can easily slide over each other, making graphite useful as a lubricant.

layered materials

Layered materials like graphite are characterized by their structure of multiple layers stacked on top of each other. Each layer can slide over the other without breaking due to the weak interlayer forces. This unique property is shared by other materials such as molybdenite and hexagonal boron nitride.

Graphite's layered nature gives it exceptional properties. For instance, it's used in pencils because the layers easily shear off onto paper. Similarly, its ability to conduct electricity is due to the delocalized electrons within the layers. This delocalization allows electrons to move freely, making graphite an excellent conductor.

Ultimately, understanding the characteristics of layered materials and their interlayer distances, like in graphite, helps in various applications in material science and engineering.