Chapter 5 – Thermal Energy and Heat 5.1 Temperature, Thermal Energy, and Heat

Essential Question O What determines the temperature of an object? O What is thermal energy?

Key Vocabulary O Temperature: a measure of how hot or cold something is; a measure of the KE of the particles in an object. O Fahrenheit scale: the scale used to measure temperature in the US. O Celsius scale: the scale used to measure temperature in most other countries.

Key Vocabulary O Kelvin scale: the scale used by many scientists to measure temperature. O Absolute zero: the lowest temperature possible; equal to zero Kelvins or -273 degrees C. O Heat: the transfer of thermal energy from a warmer object to a cooler object.

Key Concepts O Unlike Fahrenheit and Celsius scales, the Kelvin scale is separated into units called Kelvins (K). O A change of 1 K is equal to 1 degree C.

Key Concepts O At absolute zero, particles have no kinetic energy. O Thermal energy is the total energy of all the particles in an object. It depends on: O Temperature of particles O The number of particles O How the particles are arranged

Key Concepts

O The more particles an object has at a certain temp, the more thermal energy it has. O An object with a greater temp (and the same number of particles) has more thermal energy.

Key Concepts O In the transfer of heat, the warmer object will cool down and the cooler object will warm up until they are equal. O Heat is measured in the units of energy (joules – J).

Fahrenheit -Water freezes at 32 degrees and boils at 212 degrees. -There are 180 equal units (degrees) between the two. Celsius -Water freezes at 0 degrees and boils at 100 degrees. -There are 100 equal units (degrees) between the two. Key Concepts

Converting between Fahrenheit and Celsius: O From F to C: O Minus 32, multiply by 5, and divide by 9 O From C to F: O Multiply by 9, divide by 5, and add 32

IV. Exploration

V. Understanding and Applying

Chapter 5 – Thermal Energy and Heat 5.2 The Transfer of Heat

Essential Question O How is heat transferred?

Key Vocabulary O Convection: the type of heat transfer that occurs from the mixing of fluids (liquids/gases). O Convection current: a circular motion caused by the movement of fluids in convection. O Radiation: the transfer of thermal energy through electromagnetic waves; does not require matter. O Conduction: the transfer of thermal energy from one particle of matter to another through direct contact.

Key Concepts Convection O Heated air is less dense than cool air so it rises above. O When the air rises, cooler air fills its space and eventually warms and rises. O When the warm air cools, it sinks back down.

Key Concepts Radiation O Examples include sunlight and heat from a campfire

Key Concepts Conduction O Fast-moving particles at a higher temperature collide with slow-moving particles at a lower temperature, heating that object up.

Key Concepts

IV. Exploration

V. Understanding and Applying

Chapter 5 – Thermal Energy and Heat 5.3 Thermal Properties

Essential Question O How do different materials respond to heat?

Key Vocabulary O Conductor: a material that allows heat to move through it easily. O Insulator: a material that does not allow heat to move through it easily. O Specific heat: the amount of energy required to raise the temperature of 1 kg of a material by 1 K. O Thermal expansion: the expanding of matter when it is heated.

Key Concepts O Materials may be good conductors due to the types of particles they contain and how the particles are arranged. O Metals are generally good conductors. O Wood, air, and wool are examples of insulators.

Key Concepts O The temperature does not rise at the same rate for all objects. O Some objects heat up much faster than other objects – it depends on the object’s chemical makeup. O An object with a high specific heat can absorb more heat with less change in temp.

Key Concepts O You can figure out thermal energy changes using the following formula: O Energy change = (mass)(specific heat)(temperature change) O q = (m)(C)( T)

Key Concepts

O As objects become warmer, the particles in them begin moving more quickly and spread out. O The opposite happens when an object cools down. O Different materials contract and expand at different rates.

Key Concepts

IV. Exploration

V. Understanding and Applying