matter and energy chapter 4. bell work 11/3/10 1.mass = 15 gvolume = 5 ml what is the density?...
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Bell Work 11/3/10
1. Mass = 15 g volume = 5 mL
What is the density?
2.What is the volume? 3. What is the volume?
Bell Work 11/5/10
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?
4.1 VocabKinetic theory of matter – states that
all of the particles that make up matter are constantly in motion
4.1 Vocabthermometer – a
device for measuring temperature
degrees – evenly divided units of a temperature scale
Bell Work 11/8/10For 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
4.2 Vocab
Heat – a flow of energy from an object at a higher temperature to an object at a lower temperature
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 Work 11/9/10Write 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 11/10/10
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 Work 11/15/10Answer 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?