Presentation on theme: "April 15General Science Chapter 71 Solids, Liquids, and Gases Chapter 7."— Presentation transcript:
April 15General Science Chapter 71 Solids, Liquids, and Gases Chapter 7
April 15General Science Chapter 72 States of Matter All matter has mass and takes up space. Depends on temperature It can exist in 4 states Solid Liquid Gas Plasma
April 15General Science Chapter 73 Solids Have definite shape and volume always the same shape Cannot be compressed
April 15General Science Chapter 74 Liquids Have a definite volume Won’t spread out to fill container Can’t force it into smaller container Do not have a definite shape Take the shape of the container holding them Cannot be compressed
April 15General Science Chapter 75 Gases Have neither a definite shape nor a definite volume Springy – expand or contract to fill the available space Pumping air into a basketball You are compressing the air inside the ball As it gets fuller, it is harder to pump, because you must compress the air more.
April 15General Science Chapter 76 Plasma Most common form of matter in the universe Found in stars like the sun A gas-like mixture of positively and negatively charged particles
April 15General Science Chapter 77 Plasma As matter is heated, the particles move faster. They collide with greater force. When they get hot enough, they collide so hard that they break apart into smaller particles. These smaller particles are electrically charged – positive and negative
April 15General Science Chapter 78 Discussion #1 What are the 4 states of matter? What property do the states of matter depend upon? List 2-3 examples of solids, liquids and gases found in your body. All matter has __________ and takes up _________
April 15General Science Chapter 79 Crystals Particles in solids are arranged in geometric patterns called crystals Salt snowflakes
April 15General Science Chapter 710 Amorphous solids Amorphous – having no form Not made of crystals Examples Glass Some plastics Some kinds of wax Very thick liquids Old mirrors or windows – wavy and thicker at the bottom
April 15General Science Chapter 711 Kinetic Theory of matter All matter is made of tiny particles that are in constant rapid motion that collide elastically. The higher the temperature of the substance the faster the particles move within that substance. Temperature and particle speed are directly related.
April 15General Science Chapter 712 Kinetic Theory for solids In solids, the particles are held very close together They can vibrate against each other, but they cannot move out of position.
April 15General Science Chapter 713 Kinetic theory for liquids The particles in liquids are very close together They vibrate against each other, like in solids, but they can also vibrate over and around each other – they can move.
April 15General Science Chapter 714 Kinetic Theory for gases The particles in a gas are free to move around in all directions. They can separate from each other completely. They can spread out.
April 15General Science Chapter 715 Discussion #2 What are the 2 types of solids? List the 3 main parts of the Kinetic Theory of Matter. Particle speed in a substance is directly related to _____________
April 15General Science Chapter 716 Recall Information As materials heat up the particles begin to move faster, this makes them spread apart slightly in all directions. This is called _________ When sufficient heat is added or removed from a substance (which slows or increases the motion of the particles) a ___________ will occur.
April 15General Science Chapter 717 Phase Changes Solid to a liquid ---- Melting Liquid to a gas ---- Evaporation Gas to a liquid ---- Condensation Liquid to a solid ---- Freezing When sufficient heat is added or removed from a substance (which slows or increases the motion of the particles) a phase change will occur
April 15General Science Chapter 718 Phase Changes… There are 2 more phase changes that we did not discuss in Chapter 5. Deposition: When a gas changes directly to a solid without being a liquid in between. Frost, “ice” on sides of a chest freezer Sublimation: When a solid changes directly to a gas without being a liquid in between. Dry ice
April 15General Science Chapter 719 Energy and state changes If you heat ice cubes, you can measure their temperature rising. When they begin to melt, the temperature stays the same, even though you keep adding heat. This is because the particles in the ice are absorbing the energy to overcome the forces holding them together.
April 15General Science Chapter 720 Heat of fusion The amount of energy that must be added to change a material from a solid to a liquid.
April 15General Science Chapter 721 Heat of vaporization The amount of energy needed to change a material from a liquid to a gas. During the change, the temperature of the material stays the same because the particles are absorbing the energy.
April 15General Science Chapter 722 Fusion/Vaporization Melting and Freezing occur at the same temperature, so the Heat of Fusion happens for melting and freezing. Condensation and evaporation occur at the same temperature, so the Heat of Vaporization happens for condensation and evaporation.
April 15General Science Chapter 723 Heating curve for water
April 15General Science Chapter 724 Water evaporating from your skin Fast-moving water particles break away and evaporate. They take energy away from the remaining water. It is cooler than your skin, so it takes heat away from your skin. That’s why you get cold.
April 15General Science Chapter 725 Discussion #3 What 3 items did we discuss that were “recall” items from previous chapters? What are the 6 phase changes and explain each? What do we call the energy needed to change a material from a liquid to a solid? What about a gas to a liquid?
April 15General Science Chapter 726 Summary Part 1 What is the Kinetic Theory of matter? What are the 4 states of matter? What is particle speed for matter dependant upon? What are the 2 types of solids?
April 15General Science Chapter 727 Summary Part 2 What are the 2 “new” phase changes? What is the heating curve? Which would require more energy the heat of fusion of heat of vaporization? Why?
April 15General Science Chapter 728 Recall Information Temperature, Volume and Pressure all affect the Kinetic Theory Fluid: any material that can flow Temperature: The average kinetic energy of particles that make up a substance. Measured in °C, or Kelvin Volume: The capacity of an object. Measured in L, mL, cc
April 15General Science Chapter 729 Pressure The air exerts a force on everything it touches. The force is caused by the air particles colliding with their container or surroundings. Pressure is the amount of force exerted per unit of area.
April 15General Science Chapter 730 Pascal SI unit of pressure 1 Pa = 1 N/m 2 Very small unit Like a stick of butter spread out over a square meter Most pressures are given in kilopascals (kPa)
April 15General Science Chapter 731 Atmospheric pressure At sea level, the atmosphere exerts a pressure of about kPa kPa = 1 atm = 760 mmHg 29.9 inHg = 14.7 psi inHg (barometric pressure) Psi (pound-force per square inch) Pressure decreases with increasing altitude.
April 15General Science Chapter 732 What do you think? If you release a helium-filled balloon outside, will it break or return to Earth intact?
April 15General Science Chapter 733 Sealed container of gas The pressure depends on how often the particles hit the walls of the container. If you squeeze the container, making it smaller, the particles hit more often.
April 15General Science Chapter 734 Boyle’s Law If you decrease the volume of a container of gas without changing the temperature, then the pressure of the gas will increase. If you increase the volume, the pressure will drop.
April 15General Science Chapter 735 Charles’s Law If the pressure on a gas doesn’t change, then its volume will increase if temperature increases. If the temperature decreases, so does the volume.
April 15General Science Chapter 736 Charles’s Law In terms of kinetic theory, the gas particles are moving faster as they get hotter. They hit the walls more often and with more force. If the walls can move, the container will expand
April 15General Science Chapter 737 Absolute zero Charles calculated the temperature at which a gas would have zero volume. This is called absolute zero. -273°C or 0 K Why won’t a gas ever reach this temperature?
April 15General Science Chapter 738 Gay Lussac’s Law If the volume of a gas does not change, then when its temperature increases the pressure increases. OR If the temperature decreases the pressure decreases.
April 15General Science Chapter 739 Gas Law formulas Boyle’s Law Charles’s Law Gay Lussac’s Law
April 15General Science Chapter 740 Think baseball The gas laws can be remembered using baseball. It tells us the law and the constant within the law. CaP BaT GLoVe
April 15General Science Chapter 741 Discussion #4 What are the units for Pressure? What is Pressure? What are the 3 gas laws? What is absolute zero? What happens at absolute zero? What is the constant for each gas law?
April 15General Science Chapter 742 What do you think? Yeast in bread dough reacts with sugar to produce carbon dioxide. As the bread bakes, the yeast is killed, but the bread keeps rising. Why?
April 15General Science Chapter 743 Buoyant force The upward force exerted on an object by a fluid (liquid or gas). The amount of buoyant force determines whether an object will float or sink.
April 15General Science Chapter 744 Buoyant force and weight If the buoyant force is less than the weight, it will sink. If the buoyant force is equal to the weight, it will float. If the buoyant force is greater than the weight, it will rise – like a helium- filled balloon.
April 15General Science Chapter 745 Archimedes’ principle The buoyant force on an object is equal to the weight of the fluid displaced by the object.
April 15General Science Chapter 746 Wooden block When you put a wooden block in water, it pushes water out of the way until the weight of the water it has displaced equals the block’s weight. Then it floats.
April 15General Science Chapter 747 Steel block When you drop a steel block in water, it pushes water out of the way. However, even when the block is fully submerged, the weight of the water displaced is less than the weight of the block. So, it sinks.
April 15General Science Chapter 748 Steel ship If a steel block sinks, why does a steel ship float? The ship has a greater volume, so it pushes more water out of the way. The weight of the extra displaced water is equal to the weight of the steel, so the ship floats.
April 15General Science Chapter 749 Pascal’s Principle The pressure applied to a fluid is transmitted unchanged throughout the fluid. Example: When you squeeze one end of a toothpaste tube, the toothpaste comes out the other end.
April 15General Science Chapter 750 Hydraulic lifts Use Pascal’s principle to lift heavy objects. Force is applied to a small piston. The pressure from this force is transferred through the hydraulic fluid to a larger piston. The force is then used to lift an object.
April 15General Science Chapter 751 Hydraulic lift example 500 N of force is applied to a piston with an area of 5 cm 2. This piston is connected to a piston with an area of 50 cm 2. What force does the large piston exert on an object?
April 15General Science Chapter 752 Example continued This pressure is transferred to the large piston without being changed.
April 15General Science Chapter 753 Bernoulli’s Principle As the velocity of a fluid increases, the pressure exerted by the fluid decreases. This helps airplanes fly.
April 15General Science Chapter 754 Airplane wings Airplane wings are curved. The air over the top of the wing travels faster, making the pressure above the wing less than the pressure below it. This lifts the airplane.
April 15General Science Chapter 755 Why does a curveball curve? The air moves faster on the side of the ball that is spinning away from the direction of the throw. This creates a pressure difference that makes the ball curve.
April 15General Science Chapter 756 Discussion #5 What does Archimedes principle’s state? What is buoyant force? What is Pascal’s principle? What is Bernoulli’s principle?