Unit 5 Section 2 NotesUnit 5 Section 2 Notes

Matter and EnergyMatter and Energy

Kinetic Theory of Matter:

Useful for seeing differences in the 3 common states of matter on earth: solid, liquid, and gas.

Kinetic Theory of Matter3 Main Points

1. All matter is made of atoms and molecules which act like tiny particles that are always in motion.

2. The higher the temperature, the faster the particles move.

3. At the same temperature, heavier particles move slower than lighter particles.

Kinetic Theory

Using the Kinetic Theory of matter, Using the Kinetic Theory of matter, explain why a balloon filled with helium explain why a balloon filled with helium goes flat faster than one filled with goes flat faster than one filled with regular air. regular air.

According to the Kinetic Theory, at the same temperature, heavier particles move slower than lighter particles. Since oxygen & carbon dioxide are more massive than helium, they don’t escape out of the tiny microscopic holes as fast as helium.

Solid

Solid: Solid: substances have a definite volume and definite shape. Substances have a fixed position; no

freedom to change positions Particles are held closely together by

strong chemical attractions Definite melting point

Solid Diagram: Diagram:

Liquid

Liquid: substances have a Liquid: substances have a definite definite volumevolume but but no definite shape no definite shape

particles are closely packed, but can particles are closely packed, but can still slide past each other Take the shape of their Take the shape of their container Particles are close but not as close as a

solid Particles can move randomly and spread

on their own

Liquid Diagram:Diagram:

Viscosity:

Viscosity: Viscosity: resistance of a fluid to flow Determined by the attraction of particles:

the stronger the attraction, the more viscous (thick) the liquid is.

Fluids with a high viscosity flow slowly, and fluids with a low viscosity flow quickly.

What is more viscous: apple juice or maple syrup?

Gas

Gas: particles do not have a Gas: particles do not have a definite definite volume or shapevolume or shape. . Particles are in a constant state of motion

and rarely stick together Expand to fill available spaces Free to spread in all directions from areas

of high concentration to areas of low concentrations. Example: Example: scents of food or perfumescents of food or perfume

Have a Have a low densitylow density

Gas Diagram:Diagram:

Gas

Gases exert pressure Pressure: force exerted per unit area

of a substance If there is too much pressure (too many

helium particles) in a balloon, what happens?

A gas under pressure will escape the container if possible. Think about an air filled balloon that you let go.

Fluids

Fluids: substances that can spread Both liquids and gases can spread, so

they are considered fluids.

Plasma

Plasma: Plasma: does not have a definite shape does not have a definite shape or volumeor volume; considered to have the ; considered to have the properties of properties of fluidsfluids.. Most common state of matter in Most common state of matter in universeuniverse, ,

but not but not on Earth Makes up 99.9 % of the universe Plasma is superheated gas and is a

collection of free moving electrons and ions

Conducts electricity

Plasma

Examples of natural plasma on earth: lightning fire Aurora borealisAurora borealis

Artificial plasma Artificial plasma on earth includes on earth includes fluorescent lightsfluorescent lights

Energy

Energy: the ability to change or move matter Examples of energy or sources of

energy: heat, light, spring coiling, batteries

Energy must be Energy must be addedadded or or removedremoved to to cause a change in state. cause a change in state.

Energy Energy must be ADDED to melt or

evaporate substances Aluminum must be melted before it can be

recycled As aluminum particles gain heat, particles

move faster and break away from fixed positions and become liquids: called melting

Energy

Energy must be RELEASED to make a gas become a liquid or solid again. When H2O is a gas and molecules slow

down the water vapor returns to a liquid (called condensation). When molecules slow down even more, the water goes to a solid (ice).

Energy

Energy relationship between solid, Energy relationship between solid, liquid, and gas diagram:liquid, and gas diagram:

liquidliquid gasgassolidsolid

Energy ABSORBED

Energy RELEASED

Important Note:

Changing the state of matter does NOT change the substance or mass.

Water, steam, and ice are all H2O: the only change is the nature of attraction between molecules

Phase Change Diagram:

Melting

Freezing

Condensation

Vaporization

SublimationDeposition

SolidSolid

LiquidLiquid GasGas

Phase Changes Evaporation: change of a substance from a

liquid to a gas. Condensation: change of a substance from

a gas to a liquid. Sublimation: change of a substance from a

solid to a gas. Deposition: change of a substance from a

gas to a solid Example: Water vapor without becoming liquid-

this is how snow forms in clouds.

Law of Conservation of Mass

Law of Conservation of Mass states that Mass cannot be created or destroyed. Example: Burning a match: consider

what you start and end with.

Trivia Question

Trivia Question: If mass cannot be Trivia Question: If mass cannot be created or destroyed, then why do we created or destroyed, then why do we have to replace our tires when the have to replace our tires when the rubber “wears away”?rubber “wears away”?

Law of Conservation of Energy

Law of Conservation of Energy states that Energy cannot be created or destroyed. Energy can be converted from one form

to another. Example: A wristwatch: from chemical

energy to mechanical energy.