"Temperature, Thermal Energy, and Heat" Ch. 5 lesson 1

Temperature

A measure of the average kinetic energy of the individual particles in an object

Fahrenheit scale

The temperature scale used mostly in the United States, where water freezes at 32°F and boils at 212°F.

Celsius scale

The temperature scale used in most of the world, where water freezes at 0°C and boils at 100°C. Kelvin scale.

Kelvin scale

The temperature scale used commonly in science, where units are the same size as Celsius degrees but zero is set at absolute zero.

Absolute zero

The lowest possible temperature, equal to -273°C or 0 K, where all particle motion completely stops.

Thermal energy

The total kinetic and potential energy of all the particles in an object, which depends on temperature, mass, and state of matter.

Heat

The transfer of thermal energy from a warmer object to a cooler object.

Joule

The standard unit of measurement for heat and energy.

What determines an object's thermal energy?

Its temperature, the number of particles (mass), and the arrangement of its particles (state of matter).

How does thermal energy differ from temperature?

Temperature is the AVERAGE kinetic energy of particles; thermal energy is the TOTAL energy of all particles.

Which has more thermal energy: a hot cup of hot chocolate or a giant ice sculpture?

The ice sculpture, because it has vastly more particles (mass) than the small cup.

In which direction does heat always flow?

From a warmer object to a cooler object.

What happens to a substance's particles at absolute zero?

They lose all kinetic energy and completely stop moving.

Temperature change vs. Mass rule

If two objects are at the same temperature, the one with more mass has more thermal energy.

What is the formula to convert Celsius to Kelvin?

Kelvin = Celsius + 273 (K = °C + 273)

What are three factors that affect thermal energy?

Temperature, mass, and state of matter.

What is a common misconception about cold?

There is no such thing as "cold" entering an object; "cold" is just the absence or loss of heat.

The Particle Movement Diagrams

How do the particles look in a hot object versus a cold object?

• In a hot object, the particles are spread farther apart and have long, fast motion lines. In a cold object, the particles are packed tighter together and have tiny vibration lines.

2. The Thermometer Rule

How does a liquid thermometer work when it touches something hot?

• Thermal Expansion. The particles in the thermometer's liquid speed up, spread out, and take up more space, forcing the liquid to rise up the tube.

3. Energy Transformations

What happens when you rub your hands together on a cold day?

• Friction transforms mechanical energy into thermal energy, raising the temperature of your skin.

---