Warm - Up Are the following signs of physical change or chemical change? Melting Heating up Rusting Cookie rising Bubbles Gas being produced 7. Change in color 8. Solids forming 9. Dissolving 10. Precipitation 11. Cooling down 12. Release of light 13. Fire

Warm - up Round to correct sig fig answers addition / subtraction 1.25 + 0.1 = 2.25 - 0.110 = 5.0 - 0.25 = 0.80 + 0.055 = Round to correct sig fig answers multiplication / division 25.00 * 4.000 = 3.0 * 1.25 = 80.0 / 4 = 0.025 * 3 =

States of Matter Ch.3 Wu 4

Energy and the four states of matter http://ed.ted.com/on/MUriO1Ln 5

Phet States of Matter https://phet.colorado.edu/en/simulation/legacy/states-of-matter 6

How Shape & Volume Classifies Materials Materials can be classified as solids, liquids, or gases based on whether their shapes and volume are definite or variable Definition: a solid is the state in which materials have a definite shape and definite volume Definition: definite means that shape and volume won’t change unless the material is acted on by an outside force

Definition: a liquid is the state of matter in which material has a definite volume but not a definite shape Liquids will take the shape of their container

Definition: a gas is the state of matter in which a material has no definite shape and no definite volume Gases will expand to completely fill the volume & take the shape of their container

Almost all matter exists as a solid, liquid or gas on Earth This is not true for the universe In places with the temperature of stars, matter exists in a state called plasma In 1995, scientists discovered a fifth state of matter called BCE (Bose-Einstein condensate) At temperatures close to absolute zero (0 K or -273ºC), BCE groups of atoms behave as if they were a single particle

Plasma 99% of the matter in the universe Common found on the hot temperatures present in stars Ted-ed: Plasmas the spectacular and practical http://ed.ted.com/lessons/solid-liquid-gas-and-plasma-michael-murillo 13

Bose-Einstein Condensate Predicted by Einstein in the 1920s Near -273 oC or 0 K (absolute zero) Groups of atoms behave as though they were a single particle https://upload.wikimedia.org/wikipedia/commons/transcoded/d/d9/Bose-Einstein_Condensation.ogv/Bose-Einstein_Condensation.ogv.480p.webm 14

Kinetic Theory “Kinetic” = Greek for “to move” Kinetic Energy is the energy an object has due to its motion 1. That all particles of matter are in constant motion 2. There are forces of attraction among all particles of matter 15

Kinetic theory of gasses says: 1. The constant motion of particles in a gas allows a gas to fill a container of any shape or size 2. Particles in a gas are in constant, rapid, random motion 3. The motion of 1 particle of gas is unaffected by other particles of gas unless they collide 4. Forces of attraction among particles of gas can be ignored under ordinary conditions

The Kelvin Temperature Scale Directly proportional to average kinetic energy At absolute zero (0 K = -273 oC) molecular movements cease oC + 273 = K 17

3.1 Short Response Q’s How are shape and volume used to classify solids, liquids, and gases? What does the kinetic theory say about the motion of atoms? How is a gas able to fill a container of any size or shape Use kinetic theory and attractive forces to explain why a liquid has a definite volume and a shape that can vary. Explain why a solid has a definite shape and volume. How does the arrangement of atoms in most solids differ from the arrangement of atoms in a liquid? A hazardous chemical is leaking. Why are more people likely to be affected if the chemical is a gas, rather than a liquid?

Warm up

Ch 3.2 The Gas Laws Pressure is the result of a force distributed over an area P=F/A SI Unit is Pa (Pascals) = N/m2 (Newton / meter2) Collision between the particles of gas and the walls of the container cause pressure.

How heavy is air? https://www.youtube.com/watch?v=VDf00z8sMFw

Factors that affect gas pressure Temperature Volume Number of particles https://phet.colorado.edu/en/simulation/states-of-matter

1) Temperature P∝T

2) Volume P∝1/V

3) Number of Particles P∝n

As temperature inc. volume inc. Charle’s Law As temperature inc. volume inc.

As pressure inc. volume dec. Boyle’s Law As pressure inc. volume dec.

Combined Gas Law

Pressure as it applies to weather Wind blows from high to low pressure Uneven heating of the earth causes H/L pressure High pressure (cold air) higher density Low pressure (hot air) lower density

Ted-ed What Makes Wind? https://ed.ted.com/on/jW8CLfFu

3.2 Short Response How is the gas pressure produced in a closed container of gas? What 3 factors affect gas pressure? How does increasing the temperature affected the pressure of a contained gas? What happens to the pressure of a gas if its volume is reduced? How does increasing the number of particles of a contained gas affect its pressure? What happens to the pressure in a tire if air is slowly leaking out of the tire? Explain Some liquid products are sold in aerosol cans. Gas is stored in a can under pressure and is used to propel the liquid out of the can. Explain why an aerosol can should never be thrown in to a fireplace or incinerator.

3.3 Phase Changes

Definition: a phase change is the reversible physical change that occurs when a substance changes from one state of matter to another Six common phase changes: melting, freezing, vaporization, condensation, sublimation, and deposition

ex. Dry ice, snow “ghosts”

Ex. Frost

Ex. Dew, “sweat”

The temperature of a substance does not change during a phase change For example, water temperature remains constant when boiling to go from liquid to gas or when condensing from a gas to liquid Q: At what temperature does water boil and condense?

Energy is either absorbed or transferred during a phase change The amount of energy absorbed depends on the substance & is a unique physical property for each substance Definition: heat of fusion is the amount of energy absorbed when going from a solid to a liquid

Definition: exothermic changes occur when energy is released to the environment An example of an exothermic change is water freezing since it releases its heat to the environment so that it can freeze Definition: endothermic changes occur when energy is absorbed from the environment An example is water melting since it gathers as much heat as possible from the environment to melt

Concept Question When is it the coldest, before snow, when it is snowing, or after the snow when it is melting? Why?

The arrangement of molecules in water becomes less orderly as water melts and more orderly as water freezes Solid water (ice) has molecules in a fixed position that vibrate about a fixed point Freezing produces molecules in an orderly arrangement Liquid water has molecules that are attracted to each other and slide past each other due to special chemical bonds Melting allows a less orderly molecular arrangement

Definition: vaporization is a phase change from a liquid to a gas Vaporization is endothermic since liquid water absorbs energy in the form of heat from the surroundings to go from liquid to gas Definition: heat of vaporization is the amount of energy needed for a substance to change phases from liquid to gas Heat of vaporization is a unique physical property for each substance

Definition: evaporation is the process that changes a substance from a liquid to a gas below the substance’s boiling point Evaporation is a process that takes place at the surface of a liquid and occurs at temperatures below the boiling point Definition: vapor pressure is the pressure caused by the collisions of vapor on the walls of the container Vapor pressure increases as temperature increases

Boiling vs. evaporation

Q: How does surface area of a liquid affect the rate of evaporation? Definition: the boiling point is where vapor pressure equals atmospheric pressure Kinetic theory shows that as the temperature increases, water molecules move faster & faster until they have energy to overcome attractive forces of neighboring molecules

Concept Question Where does the drops of liquid on the outside of a can of cola on a hot summer day come from and how do they form? 53

Why are there clouds? https://www.youtube.com/watch?v=QC2x_RRnk8E

3.3 Short Response Name 6 common phase changes. What happens to the temperature of a substance during a phase change? How does the energy of a system change during a phase change? What happens to the arrangement of water molecules as water melts and freezes? What is the difference between evaporation and boiling? Explain why sublimation and deposition are classified as physical change. At room temperature, table salt is a solid and acetone is a liquid. Acetone is the main ingredient in nail polish remover. What conclusion can you draw about the melting points of these materials? What are the steps must occur for a water molecular to start on the surface of hot bath water and end up on the surface of a bathroom mirror? Note whether each of the phase changes that takes place during the process are endothermic or exothermic.