Definition
Heat is energy transferred between objects due to a temperature difference — measured in joules.
Temperature is a measure of the average kinetic energy of a substance's particles — measured in C, F or K.
Example 1 — Celsius to Kelvin
Convert C to Kelvin.
- .
Answer: K
Example 2 — Fahrenheit to Celsius
Convert F to Celsius.
- .
Answer: C
Definition
Solids: particles tightly packed, fixed positions, only vibrate — fixed shape and volume.
Liquids: particles close but able to move past each other — fixed volume, no fixed shape.
Gases: particles far apart, moving freely and rapidly — no fixed volume or shape.
Definition
Conduction: heat passes through a solid by vibration/collision of particles, without the particles themselves moving far. Convection: heat is carried by the actual movement of a fluid (liquid or gas). Radiation: heat travels as electromagnetic waves, needing no medium at all — this is how the Sun's heat reaches Earth.
Definition
Evaporation is the escape of the fastest (most energetic) surface particles of a liquid, turning it to vapour at any temperature (not just at the boiling point).
Remember
Evaporation increases with: higher temperature, larger surface area, lower humidity, and higher wind speed over the surface.
Quick Recap
- ●Heat = energy transferred by a temperature difference; temperature = average particle kinetic energy
- ●;
- ●Solids: fixed shape & volume. Liquids: fixed volume only. Gases: neither
- ●Conduction: through a solid. Convection: fluid movement. Radiation: electromagnetic waves, no medium needed
- ●Evaporation: surface particles escape at any temperature; faster with more heat, area, wind, less humidity
