Heat 7 Science — Revision Notes
Heat is thermal energy transfer between objects at different temperatures, measured in joules or calories. Understanding heat transfer is essential for exp
TL;DR: Heat is thermal energy transfer between objects at different temperatures, measured in joules or calories. Understanding heat transfer is essential fo…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
Heat is thermal energy transfer between objects at different temperatures, measured in joules or calories. Understanding heat transfer is essential for exp
Key Points to Remember
- Heat is the transfer of thermal energy from a hotter object to a cooler object
- Temperature is a measure of the average kinetic energy of particles in a substance
- Thermometer measures temperature and uses the expansion and contraction of liquids
- Conduction is heat transfer through direct contact between objects
- Convection is heat transfer through movement of fluids like air and water
- Radiation is heat transfer through electromagnetic waves that require no medium
- Specific heat capacity is the heat energy needed to raise the temperature of 1 kg by 1°C
- Latent heat is the heat energy absorbed or released during phase changes without temperature change
- Thermal expansion is the increase in size of objects when heated
- Linear expansion applies to one dimension, area expansion to two, volume to three
- Insulation materials reduce heat transfer by trapping air or preventing conduction
- Celsius, Fahrenheit, and Kelvin are temperature scales used globally
Important Formulas
- Heat Energy: Q = m × c × ΔT (where m is mass, c is specific heat, ΔT is temperature change)
- Temperature Conversion: °F = (9/5) × °C + 32
- Temperature Conversion: K = °C + 273.15
Key Terms
- Heat: Transfer of thermal energy from a hotter object to a cooler object
- Temperature: Measure of the average kinetic energy of particles in a substance
- Conduction: Transfer of heat through direct contact between materials
- Convection: Transfer of heat through movement of fluids due to density differences
- Radiation: Transfer of heat through electromagnetic waves without requiring a medium
- Specific Heat Capacity: Amount of heat energy needed to raise temperature of 1 kg of substance by 1°C
Frequently Asked Questions
What is the difference between heat and temperature?
Temperature measures the average kinetic energy of particles, while heat is the transfer of thermal energy between objects. You can have high temperature with little heat or vice versa
How do the three methods of heat transfer differ?
Conduction transfers heat through direct contact, convection through movement of fluids, and radiation through electromagnetic waves without requiring a medium
What is latent heat?
Latent heat is the heat energy absorbed or released when a substance changes phase, like from solid to liquid or liquid to gas, without any change in temperature
More 7 Science Revision Notes
🤖 Stuck on any of these? Ask Syllab's free AI Tutor to explain step by step →