Units 12-13

Question 1

Properties of matter (in this class):

Answer 1

1. Physical state at room temperature
2. Temperatures at which they CHANGE states
3. Density in various physical states
4. Response to different types of force
5. Color
6. Whether they conduct electricity

Question 2

What are the four states of matter?

Answer 2

Liquid, solid, gas, plasma

Question 3

Solid

Answer 3

Rigid with a fixed volume and shape.

Question 4

What size of force is required to change the shape of a solid?

Answer 4

Large force

Question 5

Liquids

Answer 5

Not rigid and change shape when poured from one container to another.

The volume of a liquid DOES NOT CHANGE when the shape of container changes.

Question 6

Gases

Answer 6

Not rigid, nor are their volumes fixed. Gases move from container to container, adopting the shape of the new container and expanding or contracting to fill its volume.

Question 7

Plasma

Answer 7

A gas of positively and negatively charged particles. The positive particles are atoms that have lost their electrons. The negative particles are the electrons that were lost.

Fluid properties.

Question 8

What is the most common form of matter in the universe?

Answer 8

Plasma

Question 9

Examples of plasma

Answer 9

Northern lights, solar winds (blowing off the sun), and fluorescent lightbulbs

Question 10

True or False: There are materials that do not fully fall into a single one of the four categories of matter.

Answer 10

True
Like Jello or silly putty

Question 11

What is the only known substance that does NOT form a solid just by cooling?

Answer 11

Helium
Must have strong pressure too

Question 12

True or False: Large changes of density occur when a material undergoes a change of state

Answer 12

True

Question 13

True or False: Generally, solids are the most dense

Answer 13

True

Question 14

True or False: Liquids are much denser than gas

Answer 14

True

Question 15

Compression force

Answer 15

A force that is applied to COMPRESS a material

Pushing force

Question 16

Tension force

Answer 16

A force that pulls at something (pulls apart) or creates tension

Pulling force

Question 17

Shear force

Answer 17

A twisting or deforming force

Question 18

True or False: Compression waves and shear waves are caused by compression and shear forces, respectively.

Answer 18

True

Question 19

How does tension force play a role in waves?

Answer 19

It pulls material back to its equilibrium point.

Question 20

True or False: Solids can sustain or “support” all three types of forces

Answer 20

True

Question 21

What does “support” mean?

Answer 21

Resists the force applied

Question 22

True or False: Liquids can “support” compression and tension forces, but NOT shear forces.

Answer 22

True

Question 23

What is the ONE type of force that a gas can “support”?

Answer 23

Compression

Question 24

Electromagnetic spectrum

Answer 24

The entire range of radiation including cosmic-ray photons, gamma rays, x rays, UV, visible light, infrared, microwaves, and radio waves.

Question 25

What is white light?

Answer 25

All the colors combined together.

Question 26

What determines the overall color of an object?

Answer 26

The portions of the spectrum that an object can absorb or reflect.

Question 27

How is color related to the internal structure of the material?

Answer 27

Colors tell us there is something DIFFERENT about the two materials. If they were the same, their color would be identical.

Question 28

Why does bright sunlight appear white?

Answer 28

Because it is giving off ALL colors of the rainbow!

Question 29

Continuous spectrum

Answer 29

Giving off all the colors that blend together to create white light (like the sun, the sun gives off a continuous spectrum).

Question 30

True or False: ALL materials give off light when they are heated to high temperatures.

Answer 30

True

Question 31

Discrete spectra

Answer 31

A spectrum of separate and distinct colors in which not all colors are present. Like gases that only give off a few colors of light when heated.

Question 32

True or False: The spectrum of colors that a material gives off is distinctive and can be used to identify it.

Answer 32

True

Question 33

True or False: Metals in a solid or liquid state ALWAYS conduct electricity

Answer 33

True

Question 34

Ionic conductor

Answer 34

Material that does not conduct electricity in the solid state, but do when molten or dissolved in water

Question 35

Example of ionic conductor

Answer 35

Salt

Question 36

Non-conductor

Answer 36

A material that does not conduct electricity in ANY of its physical states.

Question 37

Examples of non-conductors

Answer 37

Sugar and ethanol

Question 38

What is the boiling point?

Answer 38

The temperature at which a material boils.

Question 39

What is the boiling TEMPERATURE?

Answer 39

The temperature of boiling at which a substance CHANGES from a liquid to gas or vice versa

Question 40

What is the melting point?

Answer 40

The temperature at which a material melts

Question 41

What is the melting TEMPERATURE?

Answer 41

The temperature at which a substance CHANGES from a solid to liquid or vice versa

Question 42

What is plasma?

Answer 42

It is a material that is so hot the particles no longer stick together but move independently of each other.

Question 43

Why does plasma glow?

Answer 43

Because the charges are separate in plasma, they accelerate and release electromagnetic radiation.

Question 44

True or False: The melting and boiling points of a material correlate (low melting point = low boiling point, etc.).

Answer 44

TRUE

Question 45

What is a scientific model?

Answer 45

A tool we use to explain why nature behaves as it does.

Question 46

Why do scientists use models when studying matter?

Answer 46

Because the fundamental particles are too small to obtain direct or exact measurements. It's difficult or impossible to do so. So we use models to predict.

Question 47

What determines if a model is successful?

Answer 47

If it correctly predicts what will happen

Question 48

How many assumptions are part of the molecular model?

Answer 48

4

Question 49

What are the four assumptions of the molecular model?

Answer 49

1. Matter consists of tiny particles called molecules. 2. Each different kind of matter consists of a different kind of molecule. 3. Molecules in matter are in constant motion 4. Molecules move and interact in accordance with laws of motion, force, and conservation

Question 50

What are molecules?

Answer 50

They are the smallest possible fundamental/building block that retains all the physical properties of a substance.

Question 51

True or False: The differences between the molecules primarily create the different physical properties of each substance.

Answer 51

True

Question 52

True or False: Molecules NEVER stop moving

Answer 52

True

Question 53

True or False: Molecules regularly approach speeds that require the laws of relativity to be enforced.

Answer 53

FALSE

Question 54

What is Brownian motion?

Answer 54

The random motion of particles such as dust or pollen in a liquid when viewed with a microscope.

Question 55

How are the molecules in a solid packed?

Answer 55

So close together they almost touch.

Question 56

How are molecules in a liquid arranged?

Answer 56

Not packed by still relatively close.

Question 57

How are molecules in a gas arranged?

Answer 57

Only in contact with each other when they collide

Question 58

True or False: In a solid, molecules vibrate in place because they're all so close together

Answer 58

True

Question 59

True or False: Molecules in liquids are not completely free of the attraction of neighboring molecules even they they are free to move around within their container.

Answer 59

True

Question 60

True or False: Collisions between molecules can happen in solids.

Answer 60

FALSE

Question 61

What does the potential energy of a molecule depend on?

Answer 61

How close they are to other molecules

Question 62

True or False: Molecules ALWAYS have kinetic energy

Answer 62

True, because they're always moving

Question 63

What did Maxwell do for molecular theory?

Answer 63

Developed a model and formula that lets us calculate the fraction of molecules going a particular speed if we know the mass of the molecules and the temperature of the gas.

Question 64

What happens to molecules as the temperature increases?

Answer 64

They move faster on average and have a wider range of speeds.

Question 65

True or False: Maxwell's equation says that the average kinetic energy of all gases will be the same at the same temperature.

Answer 65

True

Question 66

True or False: Gas molecules that are smaller in mass will move at FASTER speeds than larger molecules

Answer 66

True

Question 67

What is the rule of temperature and molecules of any state of matter?

Answer 67

For matter in any state, temperature is a measure of the average kinetic energy of the molecules. Higher heat = faster speed (more kinetic energy)

Question 68

True or False: Liquids have higher potential energy than solids

Answer 68

True

Question 69

What happens to the potential energy of molecules when additional energy is inputted?

Answer 69

It increases

Question 70

Rank the potential energy of different matter states from least to greatest:

Answer 70

LEAST: Solids Middle: Liquids MOST: Gases

Question 71

Rank the kinetic energy of different matter states from least to greatest:

Answer 71

LEAST: Solids Middle: Liquids MOST: Gases

Question 72

Does heat increase, decrease, or stay the same when two states of matter are present (changing between states)?

Answer 72

THE SAME

Question 73

In which direction does heat energy flow?

Answer 73

From hot to cold

Question 74

What is gas pressure?

Answer 74

The sum of the collective force exerted by many gas molecules colliding over a given area at the same time (gas inside a container will always have some level of pressure)

Question 75

Does gas pressure increase or decrease as temperature increases?

Answer 75

Increase

Question 76

Why do molecules move apart with higher heats?

Answer 76

The heated molecules move more, causing greater jiggling. This jiggling covers more space, so the molecules move apart to accommodate the expanded motion.

Question 77

True or False: Faster moving gas molecules hit the walls of their container more frequently, contributing to higher gas pressure.

Answer 77

True

Question 78

What is the general rule of attraction between molecules?

Answer 78

They DO attract.