By: Andrea Kafati Marianne Loewenberg Ricardo Vásquez Wadia Simón Physical Science 9-4

1. American School of Tegucigalpa Chapter 3: Solids, Liquids, and Gases By: Andrea Kafati Marianne Loewenberg Ricardo Vásquez Wadia Simón Physical Science 9-4

2. Section 1: States of Matter • Classified as solids, liquids, and gases. • Solids, liquids, and gases may be elements, compounds, or mixtures. • To define them you need to determine their properties. A. Solids • Solids: have definite shape and volume 1.Particles in a Solid • They are fixed; closely packed arrangement of particles causes a solid to have definite shape and volume. • Particles vibrate in place.

3. Section 1: States of Matter 2.Types of Solids • Crystalline solids: solids that are made of crystals. • Examples: Salt, sugar, and snow. • Amorphous Solids: particles not arranged in a regular way. • Examples: Plastic, rubber, and glass. B. Liquids • Liquid: has definite volume but no shape of its own. 1.Particles in a Liquid • Because its particles are free to move, a liquid has no definite shape. However, it does have a definite volume. • Fluid: liquid or substance that flows.

4. Section 1: States of Matter 2.Properties of Liquids • Surface tension: result of inward pull among the molecules of a liquid that brings the molecules on the surface closer together. • Viscosity: a liquid’s resistance to flowing. Depends on the size and shape of particles and the attractions between particles. Ex: high viscosity=honey, low viscosity=water. D. Gases • Gas: Can change volume very easily. Gas is also a fluid. • As they move, gas particles spread apart, filling all the space available. As a result, gas does not have definite shape or volume.

5. Matter

6. Changes of State: MeltingPoint Boiling Point Vaporization Melting Freezing Condensation Sublimation Solids -Have definite volume and shape. Particles are in fixed and packed position, vibrating in place. -Crystalline solids:solids that are made of crystals (have repeating pattern). -Amorphous solids: solids in which the particles are not arranged in a regular pattern. -Freezing: change of state from liquid to solid. Liquids -Indefinite shape, but definite volume. Particles move closely and freely. -Surface tension: the result of an inward pull among the molecules of a liquid that brings the molecules on the surface closer together. -Viscosity: a liquid’s resistance to flowing. -Melting: change of state from solid to liquid. -Condensation: change of state from a gas to a liquid. Gases -Indefinite shape and indefinite volume. Particles move freely and are farther apart. -Vaporization: change from liquid to gas. -Evaporation: vaporization that takes place only on the surface of a liquid. -Boiling: when a liquid changes to a gas belowits surface as well as at the surface. -Sublimation: change of state from a solid to a gas. Liquid Solid Gas

7. Section 2: Changes of State A. Changes between solid and liquid: • Involves an increase in thermal energy. 1. Melting • Melting: the change in state from a solid to a liquid. • Melting point: in most pure substances, the melting that occurs at a specific temperature. (Ex: water’s melting point= 0°C). • At its melting point, the particles of a solid substance are vibrating so fast that they break free from their fixed positions. 2. Freezing • Freezing: the change of state from liquid to solid. • At its freezing temperature, the particles of a liquid are moving so slowly that they begin to form regular patterns.

8. Section 2: Changes of State B. Changes between liquid and gas: • Vaporization: the change from a liquid to a gas. • Vaporization takes place when the particles of a liquid gain enough energy to form a gas. 1. Evaporation • Evaporation: vaporization that takes place only on the surface of a liquid (Ex: water puddles that gain energy from its environment and evaporated into the air). 2.Boiling • Boiling: occurs when a liquid changes to a gas below its surface as well as at the surface (you see bubbles). • Boiling point: temperature at which a liquid boils. 3. Boiling Point and Air Pressure • The boiling point of a substance depends on the pressure of the air above it. The lower the air pressure, the less energy needed for the particles of a liquid to escape into the air.

9. Section 2: Changes of State 4.Condensation • Condensation: the opposite of vaporization, the change in state from a gas to a liquid. • Occurs when the particles in a gas lose enough thermal energy to form a liquid (Ex: clouds form from water vapor, which eventually fall as rain when its droplets get heavy enough). C. Changes between solid and gas: • Sublimation: occurs when the surface particles of a solid gain enough energy that they form a gas. • During sublimation, particles of a solid do not pass though the liquid state as they form gas. • Example of sublimation is dry ice. Because at normal atmospheric pressures it does not exist as a liquid, it turns directly into gas.

10. Project Explanation

11. Freezing: -Freezing is taking place in the water of the pond. Freezing is a change of state from a liquid to a solid. In this change of state, particles go from moving freely, to vibrating and being closely packed together. Boiling: -Boiling is taking place in the soup for Josh. During boiling, a liquid changes to a gas and vaporization takes place both at the surface and within the liquid. Particles go from being closely packed and moving freely, to moving freely and filling all the space available. Sublimation: -Sublimation takes place at the pond. The frozen water of the pond is disappearing, as sublimation is a change of state from a solid to a gas. Sublimation does not pass through the liquid state. Particles go from being closely packed together and vibrating in place, to moving freely and taking all the space available.

12. Melting: -As seen in the drawing, the ice breaks as Josh was skating. This was melting, a change from a solid to a liquid. In melting, particles go from being closely packed together and vibrating in place, to moving freely.

13. Normal Day Liquid State: -This a regular day. The pond has already melt completely, so Josh decides to fish. In this liquid state, particles are closely packed and move freely.

14. Normal Day Still Liquid State: -Summer has arrived and Josh decides to have a good tan. The pond is still in its liquid state. The particles are closely packed and move freely.

15. Evaporation: -Apparently, summer became too hot. Josh was fully tanned and the pond even evaporated. Evaporation is the change from a liquid to a gas. Particles go from moving freely and closely packed, to moving freely and taking all the space available.

16. Condensation: -After a very hot day, Josh goes inside for a glass of iced lemonade. Condensation occurs in his glass. In condensation, there is a change of state from a gas to a liquid. Particles go from moving freely and spreading apart, to moving freely and closely packed.

17. Section 3: Gas Behavior -It is important to know the relationship between temperature, pressure, and volume of a gas. A. Measuring Gases -When working with a gas, it is helpful to know its volume, temperature, and pressure. 1.Volume -Because gas particles move and fill the space available, the volume of a gas is the same as the volume of its container. 2.Temperature -The faster the particles are moving, the greater their energy and the higher the temperature.

18. Section 3: Gas Behavior 3.Pressure -Pressure: the force of its outward push divided by the area of the walls of the container. P= force/ area B. Pressure and Volume 1.Boyle’s Law -Boyle found that when the pressure of a gas at constant temperature is increased, the volume of the gas decreases. When the temperature is decreased, the volume increases. -Boyle’s law: relationship between the pressure and volume of a gas.  2.Boyle’s Law in Action -Boyle’s law also implies to situations in which the volume of a gas is changed. Then the pressure changes in the opposite way.

19. Section 3: Gas Behavior C.Pressure and Temperature -Gas particles travel individually. The faster they move, the more often they collide with the walls of their containers and the greater the force of the collisions. 1.Increasing Temperature Raises Pressure -When the temperature of a gas at constant volume is increased, the pressure of the gas increases. When the temperature is decreased, the pressure of the gas decreases. 2.Pressure and Temperature in Action -Ex: a tire. As temperature increases, so does the pressure of the air inside the tire. If pressure becomes greater, the tire will burst.

20. Section 3: Gas Behavior D. Volume and Temperature -Charles’s interest in balloon rides led him to discover how gas temperature and volume are related. 1.Charles’s Law -Charles’s law: when the temperature of a gas is increased at constant pressure, its volume increases. When the temperature of a gas is at constant pressure, its volume decreases 2.Charles’s Law in Action -The heating causes the air inside the balloon to expand. -Gases show the effects of changes in pressure, temperature, and volume.

21. Relationship

22. Pressure and volume Boyle’s Law As weights are added, the gas particles occupy a smaller volume. The pressure increases.

23. Pressure and Temperature When a gas is heated, the particles move faster and collide more with each other and with the walls of their container. The pressure of the gas increases.

24. Volume and Temperature Charles’s Law Changing the temperature of a gas at constant pressure changes its volume in a similar way.

25. Section 4: Graphing Gas Behavior • Graph: diagram that tells how two variables, or factors that change, are related. • horizontal: x-axis • vertical: y-axis A. Temperature and Volume • You can perform experiments in which you change the temperature of a gas and measure its volume. Then you interpret data by graphing. 1.Collecting data • Scientists often work with gas temperatures called kelvins (K). • To convert from Celcius degrees to kelvins (K), add 273. Use (K) to graph.

26. Section 4: Graphing Gas Behavior 2.Graphing Results • origin: line that passes through the point (0,0). • directly proportional: when a graph of two variables is a straight line passing through origin. • The graph of Charles’s law shows that the volume of a gas is directly proportional to its Kelvin temperature under constant pressure. B. Pressure and Volume • A different experiment –Boyle’s law- shows how gas pressure and volume are related when temperature is kept constant.

27. Section 4: Graphing Gas Behavior 1.Collecting data • Gas in this experiment= contained in cylinder with movable piston. Begins with the volume of the gas at 300mL. Pressure of gas is 20KPa. 2.Graphing Results • vary inversely: when a graph of 2 variables form a curve. • The graph for Boyle’s law shows that the pressure of a gas varies inversely with its volume at constant temperature.

28. Charles’s Law 80 70 60 50 Volume (mL) 40 30 20 10 0 300 200 400 0 100 Temperature (K) Directly Proportional y-axis: Responding Variable • The graph at the left illustrates Charles’s law. It shows that the volume of a gas is directly proportional to its kelving temperature under constant pressure. • Directly Proportional: a term used to describe the relationship between two variables whose graph is a straight line passing through the point (0,0), or the origin. x-axis: Manipulated Variable (0,0) Origin

29. Boyle’s Law 120 100 Pressure (kPa) 80 60 40 20 0 250 150 350 0 50 Volume (mL) Vary Inversely • This graph of data shows the relationship between pressure and volume, know as Boyle’s law. • The graph for Boyle’s law shows that the pressure of a gas varies inversely with its volume at constant temperature. • Vary Inversely: a term used to describe the relationship between two variables whose graph forms a curve that slopes downward. y-axis: Responding Variable x-axis: Manipulated Variable

30. Graphing Gas Behavior • In Charles’s law, temperature is the manipulated variable and volume is the responding variable. • The manipulated variable in Boyle’s law is volume and the responding variable is pressure. • Boyle’s law is indirect (negative) and Charles’s law is direct (positive).