Chapter 2
Energy and Matter
Energy
• Capacity to do work or produce heat
• 3 types of energy
– Kinetic—Energy in motion
– Potential—Stored energy
– Radiant—Energy from all angles
Units of Energy
• calorie- heat needed to raise the temperature
of 1 gram of water 1 degree Celsius.
• Formula 1 cal= 1 g x 1oc
• Calorie= 1000 calories or 1 kilocalorie
– A human needs 2000 Calories a day to maintain
life processes.
– Michael Phelps took in 10000-14000 Calories a
day when he was swimming in the Olympics.
The Joule
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SI unit of energy
Named after James Joule
1 cal= 4.184 j
How many joules of energy are equal to 3000
Calories?
• How many Calories are equal to 14000 j?
• To lift an apple 1 meter high takes about 1 j
Law of Conservation of Energy
• Developed by James Joule
• Energy can not be created or destroyed. It is
transferred or transformed.
Temperature
• 1st thermometer was invented by Galileo
Galilei
• Gabriel Fahrenheit made 1st good
thermometer
• Anders Celsius made a scale that was
accepted by scientists
– Freezing point of water is 0 degrees
– Boiling point of water is 100 degrees
Temperature Conversions
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oF
= oC x 1.8 + 32
oC =oF -32/1.8
K= oC + 273
oC = K - 273
Kelvin Scale
• SI unit for temperature
• Same size as celsius
– Difference is the zero point
– Zero on the kelvin scale is known as absolute zero
– The point at which all matter stops
– Has never been reached but we are close
Matter
• Anything that has mass and volume
• Six states of matter
– solid
– Liquid
– Gas
– Plasma
– Bose-Einstein
– Fermiion
Properties of Matter
• Physical Properties
– Characteristics that can be observed without
altering the identity.
– Density, color, melting point, boiling point
• Chemical properties
– Can not be observed without altering the identity
– Flammability, oxidation
Changing States
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Solid to liquid—
Liquid to gas—
Gas to liquid—
Solid to gas—
Gas to solid—
Changes in Matter
• Physical change
– Alter the form but not the identity
– Usually a state change
– Melt, rip, crush
• Chemical change
– Chemical reaction
– When something changes color or is burned.
Law of Conservation of Matter
• Developed by Antoine Lavoisier
• Matter can not be created or destroyed in any
process
Elements and Compounds
• Elements
– Substance that can not be broken down into a
simpler substance.
– Can only go as small as the atom
• Compounds
– Two or more elements chemically combined
– Can only be broken into the elements that are
present in them
Mixtures
• Blend of two or more substances that can be
separated
• Heterogeneous mixture
– Mixture with visibly different parts
– Sand and water, Italian dressing
• Homogeneous mixture
– Mixture where there is not a visible difference
– Seawater, air
Separating Mixtures
• Heterogeneous
– Filtration
• Homogeneous
– Distillation, crystallization, chromatography