Question

Which of the following is a good conductor of electricity? (a) Coal (b) Diamondl (c) Graphite (d) None

Short answer

Graphite is a good conductor of electricity.

Step-by-step solution

Analyzing Conductivity

To determine which material is a good conductor of electricity, we need to consider the structure and properties of each option: coal, diamond, graphite, and none.

Examining Coal's Properties

Coal is primarily composed of carbon with various impurities. It lacks the structural arrangement needed for efficient electron mobility, making it a poor conductor of electricity.

Examining Diamond's Properties

Diamond is also composed of carbon, but its carbon atoms are bonded in a tetrahedral lattice that does not allow for the free movement of electrons, making it an excellent insulator, not a conductor.

Examining Graphite's Properties

Graphite is composed of carbon, like coal and diamond, but its atoms are arranged in layers of hexagonal arrays. These layers are held together weakly, allowing electrons to move freely between them, making graphite a good conductor of electricity.

Conclusion

After examining the properties of coal, diamond, and graphite, it is clear that graphite has a structure that supports conductivity, unlike the others which do not. Therefore, graphite is a good conductor of electricity.

Key concepts

Properties of Carbon Allotropes

Carbon is a unique element that can form various structures, called allotropes, due to its ability to establish multiple types of bonds. This ability leads to different physical and chemical properties among its allotropes.

Three well-known allotropes of carbon are:

• Diamond: Known for its exceptional hardness and clarity. Its atoms are bonded in a strong tetrahedral lattice, making it an excellent insulator.
• Graphite: Characterized by its slippery feel and metallic luster. It consists of layers of carbon atoms arranged in a hexagonal pattern, contributing to its conductive properties.
• Coal: Mostly amorphous, consisting of carbon with various other elements and impurities. It has a more random structure and lacks the electrical conductivity of graphite.

These differing properties directly result from how the carbon atoms bond in each allotrope, impacting their practical applications in technology and industry.

Structure and Properties of Graphite

Graphite is an intriguing form of carbon due to its structure and properties that set it apart. Its unique structure comprises layers of carbon atoms arranged in a hexagonal honeycomb-like pattern. Each carbon atom is bonded to three others within the same plane through covalent bonds, while weaker forces known as van der Waals forces hold the layers together.

This arrangement imparts graphite with several distinctive properties:

• Conductivity: Electrons move easily across graphite's layers due to the weak van der Waals forces, allowing free mobility. This capability makes graphite an excellent conductor of electricity.
• Lubrication: The sliding of layers over each other gives graphite a greasy texture, making it useful as a lubricant in various applications.
• Heat Resistance: Graphite withstands high temperatures without decomposing, making it valuable in heat-intensive environments.

These properties make graphite a versatile material, particularly useful in industries requiring electrical conductivity.

Comparison of Coal, Diamond, and Graphite

The comparison of coal, diamond, and graphite reveals a fascinating spectrum of properties, all stemming from the various ways carbon atoms can bond.

Here's a quick comparison:

• Coal: It is often regarded as an energy source for fuel rather than for its electrical properties. Due to its impurities and lack of a structured atomic arrangement, coal does not conduct electricity efficiently.
• Diamond: Though brilliantly structured, its dense lattice prevents free electron movement, resulting in excellent insulating capabilities rather than conductivity.
• Graphite: Its layers enable remarkable conductivity. This makes graphite suitable for electrical applications such as electrodes and batteries.

The differences in their structures account for their varying functionalities and applications, making each carbon allotrope unique in its contribution to both natural processes and modern technology.