Heat Class 7 Science Chapter 4 (Concept Session - Ep 1) | BYJU'S - Class 7

BYJU'S - Class 6, 7 & 8・2 minutes read

The session for class 7 on the channel 6th 7th 8th focuses on exploring heat concepts through activities, demonstrations, and discussions, emphasizing the importance of temperature as a concrete measure of hotness or coldness in everyday life. Clinical thermometers are introduced as specialized tools for measuring body temperature, with precautions highlighted for accurate readings, while lab thermometers are used for objects or solutions within a specific temperature range.

Insights

  • Touch is not a reliable method to sense hot or cold, emphasizing the necessity of using temperature as a concrete measure of heat levels.
  • Clinical thermometers, designed for measuring human body temperature, use the Celsius scale primarily in India, with each degree consisting of 10 small divisions, requiring precautions like shaking before use to reset the mercury level below 35 degrees, and featuring a kink to prevent immediate mercury drop for accurate readings.

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Recent questions

  • What is the definition of temperature?

    Temperature is the degree of hotness or coldness of a body.

  • Why is a clinical thermometer used for measuring body temperature?

    Clinical thermometers are designed specifically to measure human body temperature.

  • What is the range for normal human body temperature?

    The range for normal human body temperature is 35 to 42 degrees Celsius.

  • Why are precautions necessary when using a clinical thermometer?

    Precautions for using a clinical thermometer include washing it for hygiene, not holding it by the bulb, and ensuring the mercury level is below 35 degrees.

  • Why are modern digital and infrared thermometers considered safer alternatives to mercury thermometers?

    Modern digital and infrared thermometers are safer alternatives to mercury thermometers.

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Summary

00:00

"Exploring Heat Concepts with Class 7"

  • The session is for class 7 on the channel 6th 7th 8th, focusing on heat.
  • The session aims to explore heat concepts through activities, questions, and simulations.
  • An experiment is shown to demonstrate that touch is not a reliable way to sense hot or cold.
  • The experiment highlights the need for temperature as a concrete measure of hotness or coldness.
  • Temperature is defined as the degree of hotness or coldness of a body.
  • The session emphasizes the importance of temperature in everyday life.
  • A poll question is used to engage students in understanding ascending order of temperatures.
  • The clinical thermometer is introduced as a specialized tool for measuring body temperature.
  • The construction of a clinical thermometer includes a mercury bulb, kink, capillary, stem, scale, and glass tube.
  • The clinical thermometer uses the Celsius scale, although Fahrenheit is also mentioned in some thermometers.

18:35

Temperature Measurement Devices: Celsius and Fahrenheit

  • In India, Celsius is commonly used for temperature readings, but Fahrenheit is also seen on thermometers due to historical habits.
  • Clinical thermometers are designed specifically to measure human body temperature.
  • The range for normal human body temperature is 35 to 42 degrees Celsius.
  • Each degree on a thermometer consists of 10 small divisions.
  • Shaking a thermometer before use is recommended to reset the mercury level below 35 degrees.
  • The kink in a clinical thermometer prevents the mercury from falling instantly after removal for accurate readings.
  • Precautions for using a clinical thermometer include washing it for hygiene, not holding it by the bulb, and ensuring the mercury level is below 35 degrees.
  • Lab thermometers lack a kink and are used to measure temperatures of objects or solutions, with a range from -10 to 110 degrees Celsius.
  • Lab thermometers do not require a kink because they are used directly in the substance being measured, eliminating the need for a delay in reading.
  • Handling lab thermometers with care is essential for accurate measurements and to prevent damage to the fragile bulb.

36:45

"Safe Thermometer Use for Hot Liquids"

  • Thermometer connection is crucial for measuring hot milk temperature accurately.
  • Using a laboratory thermometer for hot milk can lead to exceeding its range, risking breakage.
  • Laboratory thermometers are suitable for measuring boiling water due to their glass construction.
  • A laboratory thermometer's mercury expansion can cause breakage if used for hot liquids.
  • Proper thermometer placement is essential for accurate temperature readings.
  • Modern digital and infrared thermometers are safer alternatives to mercury thermometers.
  • Mercury in thermometers is toxic, leading to severe health issues if exposed.
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