Science Test 10/25

Question 1

What are the main 3 types of states of matter?

Answer 1

Solid, Liquid, Gas.

Question 2

Is an ice cube the same substance as water? Explain your answer.

Answer 2

An ice cube is the same substance as water, however, it is in a different state. An ice cub is solidified water.

Question 3

Does a liquid have definite volume? Explain your answer.

Answer 3

Liquids have definite volumes because the particles inside them maintain close contact with each other.

Question 4

What is an example of a liquid moving to a solid state of matter? What is this called?

Answer 4

When a liquid moves to a solid state of matter this is called the freezing point. An example of a freezing point is when water freezes to ice.

Question 5

What is an example of a solid moving to a gas? What is this called?

Answer 5

When a solid moves to a gas, this is called sublimation. An example of this process is dry ice turning into carbon dioxide.

Question 6

6. What do you think happens to the particles of a solid as it moves to the liquid phase? Describe the process.

Answer 6

When particles of a solid move to the liquid phase, they lose their fixed shape and the particles become more spread out.

Question 7

If a hot coffee cup is placed on the counter what will happen to the heat?

Answer 7

When a hot coffee cup gets placed on the counter, the heat transfers to the surroundings. When the coffee lowers the temperature, this causes a decrease in the average amount of kinetic energy. The coffee and the mug are both losing energy, but the surroundings are gaining energy.

Question 8

What role does heat play in changing states of matter?

Answer 8

Heat plays a major role during the changing states of matter. The increased/decreased energy just pushes the particles enough, to change form.

Question 9

Where might you find examples of plasma on Earth?

Answer 9

One example of plasma is the northern lights (aurora). This can be found in the northern parts of the US.

Question 10

When solids go to liquids to gas is the energy increasing or decreasing?

Answer 10

Increasing.

Question 11

When molecules move from one phase to another is it still the same substance? Provide a example.

Answer 11

They are still the same substance. There is water vapor above a pot of boiling water. That vapor (or gas) can condense and become a drop of water in the cooler air. If you put that liquid drop in the freezer, it would become a solid piece of ice. No matter what physical state it was in, it was always water. It always had the same chemical properties.

Question 12

Describe the following term: Solid

Answer 12

Anything with a definite shape and volume. Wood and ceramic used to build lab tables are solids. The molecules in the lab table still vibrate in place (because they are room temperature) but the molecules do not flow or move apart. Molecules continue to vibrate in place until all heat has been removed. At this point temperatures are at Absolute Zero (0 Kelvin or -273.15 degrees C). The molecules that make up a solid, like ice, are closely packed and can only vibrate within their fixed positions. This arrangement of the molecules, and their limited motion, are reflected in a solid’s macroscopic behavior.

Question 13

Describe the following term: Liquid

Answer 13

A substance with a definite volume but no definite shape. Water is a liquid at room temperature and pressure because the molecules of H2O can move past each other. Water is a liquid between 0 and 100 degrees Celsius. The molecules that make up a liquid, like water, are closely packed but can slip past one another within the liquid. This molecular arrangement and motion are what cause a liquid to have a changing shape and fixed volume.

Question 14

Describe the following term: Gas

Answer 14

Helium is a gas (at room temperature and pressure) because the molecules spread out and take up the entire space they are given to expand. Molecules that make up a gas have plenty of space between them and move independently from one another. This freedom of molecular motion causes a gas to have a changing shape and volume. Though water vapor is not visible, you can see how a gas can change shape and volume when you look at steam, which contains droplets of water as the vapor condenses.

Question 15

Describe what the particles look like during the solid stage.

Answer 15

*Rigid
*Fixed Shape
*Fixed Volume
*Compact

Question 16

Describe what the particles look like during the liquid stage.

Answer 16

*Not rigid
*No fixed shape
*Fixed volume

Question 17

Describe what the particles look like during the gas stage.

Answer 17

*Not rigid
*No fixed shape
*No fixed volume

Question 18

Suppose you go on a trip to the snow. You decide to play in the snow and get very cold. You then need to find a way to warm up. You are given two options to warm up. You can either dump a bucket of very warm water (100 degrees) on you or sit in a pool that is relatively warm (70 degrees). Which would you choose and why?

Answer 18

If I were very cold, I would sit in a pool that is relatively warm because dumping a bucket of really warm water would be better thus it has more thermal energy.

Question 19

What is thermal energy and temperature? How are they different?

Answer 19

Thermal energy is the total energy of the motion of the atoms and molecules. Temperature is a measure of the average kinetic energy of the particles of a substance. These two examples are different because the molecules in the cup of boiling water is greater than the average speed of the many molecules in the bowl of water.

Question 20

Describe how particles move as an object moves from a solid to a liquid to a gas.

Answer 20

In a solid the particles start to move faster as the temperature increases and eventually at the melting point of the substance, the bonds of the molecules weaken, breaking from the fixed position they were in, creating a liquid. Liquid changes into a gas when the molecules separate from each other, creating empty space, and move independently.

Question 21

What role does temperature play in changing matter from one state to another? Explain with an example.

Answer 21

The temperature changes as the state matter changes from one state to another, increasing or decreasing creating energy. As ice melts the temperature changes and state of matter changes.

Question 22

What is a example where it is difficult to determine what state of matter a substance is in? Why is it difficult to tell?

Answer 22

One example of a substance that would be hard to tell would be slush. This is difficult to tell because it involves solids> ice, and liquids > water.

Question 23

What is sublimation? What do particles do when this occurs?

Answer 23

Sublimation is the change in state of matter from a solid to gas or gas to solid. When this happens, particles instantly move from a closely packed state to a spread out state.

Question 24

What is a real world example of sublimation? What does it look like?

Answer 24

Dry ice is an example of sublimation because changes from a solid to gas. It looks like an ice cube with carbon dioxide fuming out.

Question 25

To move from a liquid to a solid what role does energy play and cause the particles to do?

Answer 25

When moving from a solid to a liquid the average amount of kinetic energy has to decrease, causing the particles to become fixed.

Question 26

To move from a liquid to a gas what role does energy play and cause the particles to do?

Answer 26

To move from a liquid to a gas the kinetic energy has to increase, causing the particles to move faster and be more spread out.

Question 27

What is the definition of a state of matter?

Answer 27

The physical form matter takes on as determined by the arrangement and motion of its atoms or molecules.

Question 28

What is heat?

Answer 28

The transfer of energy from a hot object to a colder object.

Question 29

What is the difference between heat and temperature.

Answer 29

Heat is the transfer of energy from a hot object to a colder object while temperature is the average kinetic energy.

Question 30

What is heat transfer?

Answer 30

Heat transfer is the physical act of thermal energy being exchanged between two systems by dissipating heat.

Question 31

What is Conduction?

Answer 31

Conduction occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature. Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object. As they collide, the faster molecules give up some of their energy to the slower molecules. The slower molecules gain more thermal energy and collide with other molecules in the cooler object. This process continues until heat energy from the warmer object spreads throughout the cooler object. Some substances conduct heat more easily than others. Solids are better conductors than liquids and liquids are better conductors than gases. Metals are very good conductors of heat, while air is very poor conductor of heat. You experience heat transfer by conduction whenever you touch something that is hotter or colder than your skin like when you wash your hands in warm or cold water.

**Don’t memorize all of this - extract the main parts of this.

Question 32

What is Convection?

Answer 32

In liquids and gases, convection is usually the most efficient way to transfer heat. Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. As this happens, cooler liquid or gas takes the place of the warmer areas which have risen higher. This cycle results in a continuous circulation pattern and heat is transferred to cooler areas. You see convection when you boil water in a pan. The bubbles of water that rise are the hotter parts of the water rising to the cooler area of water at the top of the pan. You have probably heard the expression “Hot air rises and cool air falls to take its place” - this is a description of convection in our atmosphere. Heat energy is transferred by the circulation of the air.

**Don’t memorize all of this - extract the main parts of this.

Question 33

What is Radiation?

Answer 33

Both conduction and convection require matter to transfer heat. Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object. For example, we feel heat from the Sun even though we are not touching it. Heat can be transmitted through empty space by thermal radiation. Thermal radiation (often called infrared radiation) is a type electromagnetic radiation. Radiation is a form of energy transport consisting of electromagnetic waves traveling at the speed of light. Radiation does not need to travel through a medium (a substance used to transmit energy).

**Don’t memorize all of this - extract the main parts of this.

Question 34

Heat Transfer is….

Answer 34

The physical act of exchanging thermal energy between two systems by dissipating heat.

Question 35

Kinetic Energy is…

Answer 35

The energy of objects from their motion.

Question 36

Thermal Energy is…

Answer 36

The total amount of kinetic energy in a object.

Question 37

Conduction is…..

Answer 37

When cold and hot objects come in contact with each other.

Question 38

Convection is…

Answer 38

When warmer fluid goes to a colder area.

Question 39

Radiation is…

Answer 39

The transfer of energy through electromagnetic energy that does not need a medium.

Question 40

An example of Convection:

Answer 40

When a hot air balloon rises due to pressure build up of hot air and the cool air lowers.

Question 41

An example of Radiation:

Answer 41

The sun radiating off heat to the earth without direct contact.

Question 42

An example of Conduction:

Answer 42

When a cold egg and hot pan comes in contact, the cold egg heats up through heat transfer.