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Particles in Motion. convection vaporization thermal conductor thermal insulator. temperature heat conduction radiation. Lesson 3-1. Kinetic Molecular Theory. Particles in Motion A. Kinetic Molecular Theory
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Particles in Motion • convection • vaporization • thermal conductor • thermal insulator • temperature • heat • conduction • radiation
Lesson 3-1 Kinetic Molecular Theory • Particles in Motion • A. Kinetic Molecular Theory • 1. The transfer of thermal energy depends on the movement of particles in the material.
Lesson 3-1 • 2. The kinetic molecular theory of matter explains how particles move. • a. Particles make up all matter. • b. Particles are in constant, random motion. • c. Particles constantly collide with each other and with thewalls of their container.
Lesson 3-1 Kinetic Molecular Theory(cont.) What are the three points of the kinetic molecular theory?
Lesson 3-1 Kinetic Molecular Theory(cont.) • 3. Temperature is the measure of the average kinetic energy of the particles in a material. • a. If the particles in a material have little kinetic energy, the material feels cold. • b. The SI unit for temperature is Kelvin (K). • c. Another temperature unit often used by scientists is Celsius (C).
Lesson 3-1 Kinetic Molecular Theory(cont.) When water is cooled to near its freezing point, interactions between water molecules push the molecules apart.
Lesson 3-1 Kinetic Molecular Theory(cont.) • 4. Thermal expansionis the increase in volume that a material undergoeswhen its temperature increases. • a. At higher temperatures, the particles in matter move faster, requiring more volume because they collide more often,pushing each other apart. • b. Thermal contraction is the decrease in a material’s volume when its temperature decreases.
Lesson 3-1 When you put a warm bottle of water in a cold refrigerator, thermal energy is transferred.
Lesson 3-1 Kinetic Molecular Theory(cont.) • 5. Kinetic energy is transferred from one material to another one when their particles collide. • 6. Heat is the movement of thermal energy from a region of highertemperature to a region of lower temperature. • 7. Materials are said to be in thermal equilibrium when the temperatures ofmaterials that are touching are equal.
Lesson 3-1 Kinetic Molecular Theory(cont.) equilibrium from Latin aequus, means “equal”; and libra, means “a balance or scale”
Lesson 3-2 • B. Heat Transfer • 1. Conductionis the transfer of thermal energy due to collisionsbetween particles in matter. • 2. Radiationis the transfer of thermal energy by electromagneticwaves. • 3. Convection is the transfer of thermal energy by the movementof the particles from one part of a material to another.
Lesson 3-2 Conduction, radiation, and convection are ways in which thermal energy is transferred.
Lesson 3-2 Heat Transfer (cont.) In what three ways is thermal energy transferred?
Lesson 3-3 Heat and Changes of State • C. Heat and Changes of State • 1. When thermal energy is added to solid ice, its temperature increasesuntil it starts to melt, changing to liquid water. • 2. When thermal energy is removed from liquid water, its temperaturedecreases until it starts to freeze, changing to solid ice.
Lesson 3-3 Heat and Changes of State (cont.) • 3. When thermal energy is added to liquid water, its temperature increasesuntil it starts to vaporize, changing to a gas. • 4. When thermal energy is removed from a gas, it changes to a(n) liquidthrough a process called condensation.
Lesson 3-3 Heat and Changes of State (cont.) • 5. Sublimation occurs when a solid absorbs energy and changes directly to a gas without first becoming a(n) liquid. • 6. Deposition occurs when a gas changes directly to a solid withoutfirst becoming a(n) liquid.
Lesson 3-3 Heat and Changes of State (cont.) sublime Science Use to change from a solid state to a gas state without passing through the liquid state Common Use inspiring awe; supreme, outstanding, or lofty in thought or language
Lesson 3-4 Conductors and Insulators • D. Conductors and Insulators • 1. Thermal energy moves quickly in a thermal conductor. • 2. Thermal energy moves slowly in a thermal insulator
Lesson 3-4 Conductors and Insulators(cont.) How do thermal conductors differ from thermal insulator?
Lesson 3 - VS • The kinetic molecular theory explains how particles move in matter.
Lesson 3 - VS • Thermal energy is transferred in various ways by particles and waves. • Materials vary in how well they conduct thermal energy.