Matter and Energy

Chapter 4

• Make sure you have everything you need to go home

• Make sure your phone is turned off

• Get out your bell work make sure your name is on it, I am going to collect it in a minute

Bell Work

Complete the front side of the sheet by the sinks.

Bell Work

Please show all your work! This means write down the formula, write down the numbers you are using, then solve the problem.

• Mass = 15 g volume = 5 mL

What is the density?

2. Length = 3 cm Width = 5 cm Height = 4cm

What is the volume?

4.1 VocabKinetic theory of matter – states that

all of the particles that make up matter are constantly in motion

4.1 Vocab

temperature – a measure of the average kinetic energy of all the particles in an object

4.1 Vocabthermometer – a

device for measuring temperature

degrees – evenly divided units of a temperature scale

Thermal Expansion

All gases, many liquids, and most solids expand when their temperature increases.

Bell WorkFor each description write which

temperature scale it matches (Fahrenheit or Celsius)

1. Freezing point of water is 0 degrees

2. Freezing point of water is 32 degrees

3. Used by scientists and most countries

4. 100 units between freezing and boiling points of water

Bell Work

1. Can an oxygen canister ever be half empty? Explain.

2. How does tea flavor spread from a tea bag throughout a cup of hot water?

3. What instrument is used to measure temperature?

4.2 Vocab

Heat – a flow of energy from an object at a higher temperature to an object at a lower temperature

4.2 Vocabthermal energy – the total amount of

kinetic energy of particles in an object

4.2 Vocab

calorie – the amount of energy needed to raise the temperature of 1 gram of water by 1 degree C

joule – scientific unit for measuring energy (1 calorie = 4.18 joules)

Food Calorie• One Calorie is actually

one kilocalorie or 1000 calories

• One Calorie in food contains enough energy to raise the temperature of 1 kilogram of water by 1 degree C

4.2 Vocab

specific heat – the amount of energy required to raise the temperature of one gram of a substance by one degree Celsius

Bell WorkWrite the definition and correct term for each.

1. The flow of energy from a warmer object to a cooler object.

2. The average kinetic energy of particles in an object.

3. The total kinetic energy of particles in an object.

4. The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celcuis.

Bell Work

1. How many calories are needed to raise the temperature of 75 grams of water from 5 degrees Celsius to boiling?

2. How many calories are needed to raise the temperature of 50 grams of water from 30 degrees Celsius to boiling?

Energy moves as heat in three ways

Conduction – moves energy from one object to another when they are physically touching

Convection – energy is transferred in gases and liquids. Occurs when a warmer, less dense area of gas or liquid is pushed up by a cooler, more dense area of the gas or liquid.

Radiation – energy travels across distances in the form of electromagnetic waves

Conduction

• Occurs any time that objects at different temperatures come in contact with each other

• Can also occur within a

single object (spoon)

• Some materials

transfer kinetic energy

of particles better than

others

Conductors – materials that transfer energy easily

Insulators – materials that do not transfer energy easily or are poor conductors

ConvectionA cycle in nature responsible for most winds and ocean

currents1. cooler, denser air flows in underneath the warmer, less dense air, and pushes the warmer air upward2. When this air cools, it becomes more dense than the warmer air beneath it3. The cooled air sinks and moves under the warmer air

Radiation

• Energy that travels as electromagnetic waves

• Includes visible light, microwaves, and infrared light.

• Sun is the most significant source

• All objects, even humans, emit radiation and release energy to their surroundings

• Can move through empty space (Sun to Earth)

Bell WorkAnswer the following questions

imagining that a person is sitting in a chair in front of a fireplace.

1. What are two ways in which the person is warmed by the fire?

2. If a dog is sitting in between the person and the fireplace why might it be warmer where the dog is sitting?

3. Where in the room would conduction be most noticeable?

Bell Work

Please complete #1- 5 on page 95 then get out your study guide and review for the test.

Bell Work 11/18/10

Please answer #1-5 on page 37. These will be taken for a grade so make sure you do your best.