TEACHGYAN • CLASS 6 SCIENCE • CURIOSITY
Chapter 7 – Temperature and its Measurement
Hot & cold • Temperature • Thermometers • Celsius scale • Safe measurement • MCQs • Worksheet
Chapter focus: Our sense of touch can tell us whether something feels hot or cold, but it is not a reliable way to measure temperature. Thermometers provide numerical measurements using a defined scale.
🎯 Learning Goals
- Distinguish feeling hot/cold from measuring temperature.
- Explain temperature as a measurable physical quantity.
- Understand the Celsius scale used in everyday measurements.
- Identify parts and uses of common thermometers.
- Read a thermometer correctly.
- Use thermometers safely and avoid contamination or breakage.
🌡️ 1. Hot and Cold
Objects can feel hotter or colder than one another. However, our skin can be misleading. A metal object and a wooden object kept in the same room may feel different even though they are at the same temperature.
📏 2. What Is Temperature?
Temperature is a measurable quantity that tells us how hot or cold a body is. A thermometer gives a numerical temperature reading, making comparison more precise.
🌡️ 3. Thermometer
A thermometer is an instrument used to measure temperature. Different thermometers are designed for different purposes. Digital thermometers use electronic sensors; liquid-in-glass thermometers use the expansion of a liquid.
📐 4. Celsius Scale
Temperature in school science is commonly expressed in degrees Celsius, written as °C. The numerical value should always be accompanied by the unit.
🩺 5. Clinical Thermometer
A clinical thermometer is designed for measuring human body temperature. Modern digital clinical thermometers are widely used. Follow the manufacturer’s instructions and hygiene precautions when using one.
🧪 6. Laboratory Thermometer
A laboratory thermometer is designed to measure the temperature of substances in experiments over an appropriate range. It should not be used to measure body temperature unless specifically designed and approved for that purpose.
👁️ 7. Reading a Thermometer
- Use the correct thermometer for the purpose.
- Ensure the instrument is in good condition.
- Place the sensor or bulb appropriately as instructed.
- Wait for the reading to stabilise where required.
- Read at the correct position and note the unit °C.
- Clean or store the instrument according to instructions.
⚠️ 8. Safety and Care
- Do not use a damaged thermometer.
- Do not shake or handle a liquid thermometer carelessly.
- Never put a laboratory thermometer in your mouth.
- Do not touch a hot vessel directly; use suitable equipment.
- Follow teacher instructions during practical work.
🔬 9. A Simple Investigation
Place water at different temperatures in separate containers and measure each using the same suitable thermometer. Record the readings and compare them. Avoid very hot water and use teacher supervision in a classroom.
📋 Worked Examples
Example 1 – Why Touch Is Not Enough
A metal spoon and wooden spoon kept in the same room can feel different to the hand. A thermometer can be used to compare their temperatures objectively.
Example 2 – Recording Temperature
If a thermometer reads 28 on the Celsius scale, the correct record is 28 °C, not simply “28”.
Example 3 – Choosing an Instrument
Use a suitable clinical thermometer for body temperature and an appropriate laboratory thermometer for an experiment. Instruments should not be interchanged casually.
🧠 Think Like a Scientist
- Why is touch not a reliable measuring instrument?
- Why must a temperature reading include a unit?
- Why are different thermometers made for different purposes?
- Why should a laboratory thermometer not normally be used in the mouth?
- How can repeated measurements improve confidence in an observation?
📝 Important Practice Questions
- What is temperature?
- Why can our sense of touch be misleading?
- What is a thermometer?
- What is the common unit used to express temperature in school science?
- What is a clinical thermometer used for?
- What is a laboratory thermometer used for?
- Why should a thermometer be read carefully?
- Why should a damaged thermometer not be used?
- Why must units be written with readings?
- Write three thermometer safety precautions.
🔥 Competency / HOTS
- Two objects feel different to your hand but are measured at the same temperature. Explain how this is possible.
- Design a safe investigation comparing three samples of water at different temperatures.
- A student writes “32” in a results table. What important information is missing?
- Why would a clinical thermometer and a laboratory thermometer not necessarily have the same design or range?
- A thermometer gives a different reading each time. List possible reasons and what you would check.
🧩 MCQ Practice
- Temperature is measured using a — A. thermometer B. ruler C. balance D. compass
- The common school unit for temperature is — A. degree Celsius B. metre C. kilogram D. litre
- Our sense of touch is — A. not a precise temperature measurement method B. always exact C. a thermometer D. a standard unit
- A clinical thermometer is intended mainly for — A. body temperature B. measuring length C. measuring mass D. measuring rainfall
- A laboratory thermometer is used mainly for — A. experimental temperature measurements B. measuring body height C. measuring distance D. weighing objects
- A temperature reading should include — A. numerical value and unit B. number only C. colour only D. name only
- A damaged thermometer should be — A. avoided and reported/replaced B. used carefully anyway C. heated strongly D. put in the mouth
- Temperature of a hot object is generally — A. higher than that of a cooler object B. always zero C. impossible to measure D. unrelated to measurement
Answer Key: 1-A, 2-A, 3-A, 4-A, 5-A, 6-A, 7-A, 8-A
📄 Printable Worksheet
- Define temperature.
- Explain why touch is not a reliable way to measure temperature.
- Draw and label a simple thermometer diagram.
- Write the unit used for temperature in this chapter.
- Differentiate clinical and laboratory thermometers.
- List five safety precautions.
- Record three safe temperature measurements from a classroom activity.
- Explain why the unit must be written with a reading.
- Suggest reasons for inconsistent thermometer readings.
- Write a short procedure for measuring water temperature safely.
🔁 Quick Revision
| Concept | Remember |
|---|---|
| Temperature | Measurable quantity indicating how hot or cold something is. |
| Thermometer | Instrument used to measure temperature. |
| °C | Degree Celsius, a common temperature unit. |
| Clinical thermometer | Designed for body-temperature measurement. |
| Laboratory thermometer | Designed for suitable experimental temperature measurements. |
| Safety | Use the correct instrument and follow handling instructions. |
✅ Mastery Checklist
- ☐ I can explain temperature.
- ☐ I understand why touch is not precise.
- ☐ I can identify common thermometer types.
- ☐ I can record temperature with °C.
- ☐ I can read and handle a thermometer safely.
- ☐ I can design a simple temperature investigation.