Chapter 16 States of Matter

Chapter 16: State of Matter Section 1: Kinetic Theory

You will learn how to… Explain the kinetic theory of matter Describe particle movement in the 4 states of matter Explain particle behavior at the melting and boiling points This is important because: You can use energy that is lost or gained when a substance changes from one state to another.

What is matter? Matter- is anything that has mass and occupies space Four States of Matter Solid Liquid Gas Plasma

Kinetic Theory Kinetic Theory- an explanation of how particles in matter behave

3 Assumptions of the Kinetic Theory 1. All matter is composed of small particles (atoms, molecules, and ions) 2. These particles are in CONSTANT, random motion. 3. These particles are colliding with each other and the walls of their container.

Thermal Energy Thermal Energy- the TOTAL energy of a material’s particles. Thermal Energy = kinetic energy (vibrations) + the potential energy (movement within and between the particles.)

Question What do you think would happen to the speed of a substance’s particles, IF the TEMPERATURE was decreased ( )?

Answer…… When the temperature of a substance DECREASES ( ), the particles will have LESS thermal energy and will vibrate

Question What will happen to the speed of the particles IF you INCREASE ( ) the temperature?

Answer…… When the temperature of a substance INCREASES ( ), the particles will have MORE thermal energy and will vibrate

Average Kinetic Energy Temperature is used to explain how HOT or COLD an object is. In science, temperature means the average kinetic energy in the substance, or how FAST the particles are moving.

Average Kinetic Energy Let’s Look…. Temperature 0C0C Speed of Particles Average Kinetic Energy HOT100 0 CFASTHIGH COLD00C00CSLOWLOW ABOLUTE ZERO CVERY SLOW VERY LOW

Question? TRUE OR FALSE The molecules of frozen water have a HIGHER average kinetic energy than the molecules of boiling water.

Answer…… The molecules of frozen water have a LOWER average kinetic energy than the molecules of boiling water. The molecules of frozen water are moving slow so the average kinetic energy is low.

States Of Matter Solid Liquid Gas Plasma

States of Matter Solid State Definite Shape Definite Volume The attraction between the particles is STRONG The particles are held CLOSE together

States of Matter Liquid State NO definite Shape Definite Volume The attraction between the particles is NOT TOO strong The particles FLOW past each other

States of Matter Gas State NO definite Shape NO definite Volume The attraction between the particles is VERY WEAK The particles are very FAR apart

States of Matter Plasma State NO definite Shape NO definite Volume The attraction between the particles is EXTREMELY weak The particles are very FAR apart Plasma is matter consisting of positively and negatively charged particles. Plasma exists where the temperature is EXTREMELY HIGH (ex. lightning bolts, sun, neon and fluorescent tubes)

States of Matter SolidLiquid Gas ADD HEAT REMOVE HEAT

This graph shows the heating curve of water. At A and C the water is increasing in kinetic energy. At B and D the added energy is used to overcome the bonds between the particles.

Question? Can you find 3 states of matter in this picture?

Melting Point Melting Point- the temperature at which a solid begins to liquefy SOLID  LIQUID Ex. Ice  Water Heat of Fusion- amount of energy needed to change a substance from solid phase to a liquid phase

Boiling Point Boiling Point- the temperature at which the pressure of the vapor in the liquid equals the pressure of the vapor on the surface of the liquid LIQUID  GAS Ex. Water  Water Vapor Heat of vaporization- the amount of energy needed to change a liquid at its boiling point to a gas

Thermal Expansion Thermal expansion- an increase in the size of the substance when the temperature is increased Ex. Concrete walkways Concrete absorbs heat and expands, so some concrete walkways have expansion joints (gaps) to prevent it from cracking.

Contraction Contraction- a decrease in the size of the substance when the temperature decreases (shrinks) Ex. The liquid in a thermometer contracts (shrinks) as the temperature cools.

Expansion and Contraction Heating the air in a hot air balloon causes the distance between the particles in the air to expand. The air in the hot air balloon becomes less dense, and it rises! Question: What happens if the air inside of the balloon is cooled?

So Tell Me…. When the temperature INCREAES ( ), the particles of solids, liquids and gases will expand. When the temperature DECREAES ( ), the particles of solids, liquids, and gases will contract.

Strange Behavior of Water Question: What happens to a bottle of water when you put it in the freezer?

Water is the EXCEPTION! Water expands when the temperature decreases.

Strange Behavior of Water Water is an EXCEPTION to the thermal expansion rule! Water molecules are partially positive and partially negative, so when water freezes the molecules orient themselves according to charge, and empty spaces occur in the structure. Water EXPANDS when the temperature decreases ( ) Water CONTRACTS when the temperature increases ( )

Chapter 16: Section 2 Properties of Fluids You will learn about……… Properties of fluids  Viscosity  Density  Buoyancy

Definition of FLUID Fluid- materials that flow. GASES and LIQUIDS are fluids. Water = LIQUID Water Vapor = GAS

Viscosity Viscosity- a fluids RESISTANCE to flow Ability to FlowResistance LevelViscosity LevelExample Flows FastLittle to no resistanceLOWWater Flows SlowA lot of resistanceHIGHSyrup

Some fluids move slowly. They have a high viscosity. Syrup pours slowly. It is very viscous. Syrup flows SLOW, so it has a HIGH viscosity level.

Viscosity Question: What happens to the viscosity of syrup after heating it?

Viscosity Glue is also viscous.

Viscosity Water pours quickly. Some fluids move quickly. They have a low viscosity. It is less viscous.

Density Density- mass per unit volume of a material Density of water 1 g/ml The density of the object is LESS than water (1g/ml).  FLOATS The density of the object is MORE than water (1g/ml).  SINKS

Density Column True or False Oil is more dense than alcohol and less dense than water. Water Density = 1g/mL Oil Density =.96 g/mL Alcohol Density =.75 g/mL

Answer…. Oil is more dense than alcohol and less dense than water. Water Density = 1g/mL Oil Density =.96 g/mL Alcohol Density =.75 g/mL

Buoyancy Buoyancy is the UPWARD force of a fluid on an object. Buoyant Force

Buoyancy Another example of buoyancy is a hot air balloon. The air, which is a fluid, buoys the balloon. Buoyant Force

Buoyancy Buoyant Force Some organisms use buoyancy to move.

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Chapter 16: States of Matter Section 3 Behavior of Gases

What will you learn… How a gas exerts pressure on its container How a gas is affected when pressure, temperature, or volume is changed This is important because: It helps explain and predict the behavior of gases. This is useful because we live in a sea of air.

Remember…. The atmosphere is a FLUID because it is composed of gases.

Particle Collision The gas particles in the air are constantly colliding with anything in their path. The collisions of these particles in the air result in atmospheric pressure.

Did you know… Balloons and bicycle tires remain inflated because of collisions the air particles have with the walls of their container. These collection of forces, caused by the collisions of the particles pushes the walls of the container outward.

Let’s Look…

What if….. What would happen if more air was pumped into the balloon?

Answer.. If more air was pumped into a balloon, the number of air particles would INCREASE and the balloon would expand.

Pressure VS Volume Question: If all of the air was collected from the gym and placed in a closet, what would happen to the pressure in the closet?

Pressure VS Volume Answer: If you squeeze gas into a smaller space, the gas particles will strike the walls of the container more often….causing an INCREASE in pressure.

Pressure VS Volume Question: If all of the air was collected from a closet and placed in the gym, what would happen to the pressure inside of the gym?

Pressure VS Volume Answer: If you give the gas particles more space, they will hit the walls LESS often…gas pressure will be REDUCED.

Boyle’s Gas Law Boyle’s Gas Law states: DECREASE ( )in volume of container  INCREASE ( ) in pressure…. INCREASE ( ) in volume of container  DECREASE ( ) in pressure. Temperature is CONSTANT

Boyle’s Gas Law (Initial Pressure X Initial Volume) = (Final Pressure X Final Volume) P 1 V 1 = P 2 V 2 Temperature is Constant!

Pressure VS Temperature Question: What do you think will happen if you increase the temperature of a pressurized spray canister? Ex. Hair spray

Pressure VS Temperature Answer: If you increase the temperature of a pressurized spray canister (Hair spray), the canister would EXPLODE due to the INCEASED pressure caused by the rapidly moving gas particles against its walls.

Question? How are hot air balloons inflated?

Answer…. Hot air balloons are inflated because heat causes the gases to expand. The gas particles in hot air are father apart than in the cool air, the hot air is less dense than the cool air so it rises!

Charles’s Gas Law Charles’s Gas Law states: Temperature DECREASES ( )  VOLUME DECREASES ( ) Temperature INCREASES ( )  VOLUME INCREASES ( ) Pressure is CONSTANT

Charles’s Gas Law T 1 / V 1 = T 2 / V 2 1 = Initial or Start 2 = Final

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