Activity 3.5 NCERT Class 10 Science, Chapter 3 Metals and Non-metals
The activity asks us to heat a metal wire which is attached to a pin at its corner by a wax.
Observation:
The pin drops immidiately once we start heating the wire.
Explanation:
Metals are a good conductor of heat. Here, once we start heating, heat transfers to the area of wax. It melts the wax. So, the pin drop on the table.
Inference/conclusion:
This experiment demonstrates that metals are a good conductor of heat.
Application:
Processor cooler in computers and laptops: In a computer and a laptop CPU is the most important chip. During data processing, it generates a lot of heat. To dissipate the heat, a CPU is connected to a copper or aluminium heat sink. Due to the thermal conductivity of metals heat transfers to the heat sink. A fan at the sink blows the hot air outside.
Cooking utensils: Cooking utensils consists of a metal or metal alloys. It receives heat from the gas stove and transfers heat to the food.
Facts:
Metals have free electrons in their valance shell. When we heat a metal, their electrons vibrate and transfer heat to another electron. As a result, metals are a good conductor of heat.
Next: Experiment to demonstrate metals are a good conductor of electricity, Activity 3.6.
See also: List of metals that we use as wire, Activity 3.4.
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