Presentation on theme: "Notes – Changes in States of Matter"— Presentation transcript:
1 Notes – Changes in States of Matter Chapter 6, Lesson 2
2 Temperature, Thermal Energy, & Heat Changes in energy can cause matter to change from one state to another.A state change happens because of the change in motion of particles in an object.Matter Changing State
3 Temperature, Thermal Energy, & Heat Even when an object is not moving, the particles in the object are moving.The particles have kinetic energy, which is energy of moving things.The gas particles inside the balloon have energy because they are moving.
5 Temperature, Thermal Energy, & Heat Temperature is a measure of the average kinetic energy of the particles in a material.Particles in matter move faster as the temperature increases.lower temperaturehigher temperature
6 Temperature, Thermal Energy, & Heat A thermometer is used to measure temperature.Particles in the thermometer’s gauge increase their speed when heated and start moving farther apart, causing the liquid in the thermometer to rise.
7 Temperature, Thermal Energy, & Heat Particles in a substance have potential energy.Potential energy decreases as particles move closer together.Potential energy increases as particles move farther apart.
9 Temperature, Thermal Energy, & Heat The total energy of the particles of a substance is its thermal energy.Includes kinetic energy and potential energy of a substance’s particlesA substance’s liquid state has more thermal energy than its solid stateA substance’s gas state has more thermal energy than its liquid or solid state.
18 Vaporization liquid → gas Thermal energy is absorbed. Particles become too spread out and the attractive forces are too weak to keep the particles close together.Vaporization can occur both at the surface and inside the liquid.
19 Vaporization: Boiling Vaporization that occurs inside the liquid.Boiling point refers to the temperature that boiling occurs in a substance.
21 Vaporization: Boiling The boiling point depends on the pressure exerted on the liquid.Bubbles in the liquid must form for boiling to occur.As air pressure increases, it becomes harder for the bubbles to form.The boiling point increases as air pressure increases.
22 Vaporization: Evaporation Evaporation is vaporization that occurs at the surface of a liquid.Evaporation occurs both at the boiling point and temperatures below the boiling point.
23 Vaporization: Evaporation The liquid gains thermal energy, and molecules on the surface gradually escape into the atmosphere(i.e.) water cycle, a puddle after rain, sweating to cool you down
24 Condensation gas → liquid Thermal energy is released. The gas particles slow down and move closer together until the attractive forces hold them together and a liquid forms.
33 1. The point at which a liquid changes to a gas is called ____. 6.2 Changes in States of Matter1. The point at which a liquid changes to a gas is called ____.A melting pointB freezing pointC condensation pointD boiling point
34 2. A liquid can change to a gas through ____. A evaporation B freezing 6.2 Changes in States of Matter2. A liquid can change to a gas through ____.A evaporationB freezingC meltingD sublimation
35 3. Thermal energy must be ____ when a liquid changes to a ____. 6.2 Changes in States of Matter3. Thermal energy must be ____ when a liquid changes to a ____.A lost; gasB gained; solidC lost; solidD increased; solid
36 4. Sublimation occurs when a solid changes into a ____. A liquidB gasC plasmaD steam
37 5. As air pressure ____, the ____ of a liquid increases. A decreases; boiling pointB decreases; freezing pointC increases; freezing pointD increases; boiling point
38 6. Adding thermal energy can ____ or ____. SCI 3.e6. Adding thermal energy can ____ or ____.A lower temperature; change the state of matterB increase temperature; lower temperatureC increase temperature; change the state of matterD remove kinetic energy; change the state of matter
39 A The glass of water at 30°C has lower average kinetic energy. SCI 3.e7. One glass of water has a temperature of 30°C and another glass of water a temperature of 40°C. Which is true?A The glass of water at 30°C has lower average kinetic energy.B The glass of water at 40°C has lower average kinetic energy.C The two glasses have equal average kinetic energy.D none of the above