Identify the non-metal, having high thermal conductivity.
Understanding Thermal Conductivity in Materials
Thermal conductivity is a property of a material that describes its ability to conduct heat. Materials with high thermal conductivity transfer heat efficiently, while materials with low thermal conductivity are good thermal insulators, meaning they resist heat flow.
Generally, metals are known for having high thermal conductivity, which is why they are used in applications like cooking pots and radiators. Non-metals, on the other hand, are typically poor conductors of heat and are often used as insulators.
However, the question asks to identify a non-metal that has relatively high thermal conductivity among the given options.
Analyzing the Options for Thermal Conductivity
- Wood: Wood is a natural organic material and a non-metal. It is widely known for being a poor conductor of heat, making it a good insulator. Its thermal conductivity is quite low.
- Water: Water is a common liquid and a non-metal compound (\(H_2O\)). Its thermal conductivity is higher than that of air or typical insulators like wood, but it is still significantly lower than that of metals.
- Ice: Ice is the solid phase of water. When water freezes into ice, its molecular structure changes. Ice crystals have a more ordered structure than liquid water, which allows phonons (vibrational energy carriers) to travel more efficiently. As a result, ice has significantly higher thermal conductivity compared to liquid water. While still much lower than metals, it is relatively high for a common non-metal.
- Insulating brick: Insulating bricks are specifically manufactured to reduce heat flow. They are made from porous ceramic materials (non-metals) that trap air, further reducing their thermal conductivity. They are designed to be excellent thermal insulators, not conductors.
Comparing the thermal conductivities of these materials:
| Material | Type | Typical Thermal Conductivity (W/m·K) | Relative Conductivity (among options) |
|---|---|---|---|
| Wood (typical) | Non-metal | 0.04 - 0.12 | Very Low (Insulator) |
| Water (at 20°C) | Non-metal | ~0.6 | Low |
| Ice (at 0°C) | Non-metal | ~2.2 | Relatively High (for a non-metal) |
| Insulating brick | Non-metal (ceramic) | 0.05 - 0.2 | Very Low (Insulator) |
Based on these typical values, ice has the highest thermal conductivity among the given options. Therefore, ice is the non-metal listed that has relatively high thermal conductivity compared to the others.
Conclusion
Among the given options, Ice is the non-metal that possesses the highest thermal conductivity. While metals are generally much better conductors, ice is notably better at conducting heat than liquid water, wood, or materials designed as insulators like insulating brick.
Revision Table: Key Concepts
| Term | Definition | Property Related to Heat |
|---|---|---|
| Thermal Conductivity | A measure of a material's ability to conduct heat. | High value means good heat conductor; Low value means good thermal insulator. |
| Conductor | A material that allows heat (or electricity) to flow easily. | High thermal conductivity. Metals are typically good conductors. |
| Insulator | A material that resists the flow of heat (or electricity). | Low thermal conductivity. Non-metals often act as insulators. |
Additional Information on Thermal Properties
The thermal conductivity of a material can depend on several factors, including temperature, phase (solid, liquid, gas), and composition. For example, the thermal conductivity of water changes significantly when it freezes into ice. The difference in thermal conductivity between ice and liquid water at their phase transition point (\(0^\circ\text{C}\)) is quite substantial.
- Solids generally have higher thermal conductivity than liquids and gases because molecules are closer together and interactions are stronger.
- In solids, heat is primarily conducted through vibrations of the lattice structure (phonons) and, in metals, also by the movement of free electrons. Non-metals lack free electrons, so heat conduction relies mainly on lattice vibrations.
- The relatively high thermal conductivity of ice compared to liquid water is due to the specific arrangement and strong hydrogen bonding in the ice crystal structure, which facilitates the efficient transfer of vibrational energy.
Similar Questions
"Pathfinder", an American Spacecraft, landed on the planet _______ in 1997.
- A/an ______ circle is a circular centre line on a drawing containing the centres of holes about a common centre.
- Which of the following is an example of a third-class lever?
_______ is the distance from the pitch circle to the bottom of the tooth space in a gear.
In a Class 3 lever, the effort and load move:
Important Questions from Miscellaneous
A stone is thrown horizontally from the top of a 20 m high building with a speed of 12 m/s. It hits the ground at a distance R from the building. Taking g = 10 m/s2 and neglecting air resistance will give :
A mass is attached to a spring that hangs vertically. The extension produced in the spring is 6 cm on Earth. The acceleration due to gravity on the surface of the Moon is one-sixth of its value on the surface of the Earth. The extension of the spring on the Moon would be:
Directions: Each item in this section consists of a sentence with an underlined word followed by four words (a), (b), (c), and (d). Select the option that is opposite in meaning to the underlined word and mark your response in your Answer Sheet accordingly.
The deluge affected the population.The major source of vitamins and minerals for vegetarians is
Which of the following statements about the Deccan Riots Commission is/are correct?
1. The Commission did not hold enquiries in the districts which were not affected.
2. The Commission did record the statements of ryots, sahukars and eye-witnesses.
Select the correct answer using the code given below:
