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Review for Science Final. Electromagnetic Waves. Energy is not a substance that has mass and volume. We know that energy exists because of its effect on matter (the things around us). Light is a form of electromagnetic energy and creates vibrations in the form of waves. - PowerPoint PPT Presentation
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Review for Science Final
.
Electromagnetic Waves
Energy is not a substance that has mass and volume.
We know that energy exists because of its effect on matter (the things around us).
Light is a form of electromagnetic energy and creates vibrations in the form of waves.
.
Physical Properties of Matter
Physical properties can be observed without changing the identity of the substance:
- Color - Smell - Hardness - Luster - Phases of matter
(solid/liquid/gas)
Physical Properties of Matter
Mass – the amount of matter in an object
If the ice melts, is there still the same amount of mass in the glass?
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Physical Properties of Matter
Volume – the amount of space taken up by an object.
- mL for liquids - cm³ for solids
• .
Physical Properties of Matter
Density – the amount of mass in a certain volume of material.
- Find the mass- Find the volume- Divide the mass by the
volumeDensity (g/cm³) = mass (g) volume (cm³)
What instruments could be used to find the density of the cube?
Physical Properties of Matter
Density of liquids: Some liquids float on others forming layers.
Which is denser, karo syrup or vegetable oil?
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Physical Changes
A physical change is a change in size, shape or state without forming a new substance.
Physical Changes State of matter: Add heat: particles move faster and spread apart - solid > liquid > gas Take away heat: particles slow down and move closer together - solid < liquid < gas
Elements and Atoms
An element is a substance that cannot be broken down any further into anything simpler.
Atoms are the smallest particle of an element that have the same chemical properties as the element.
Chemical Changes
A chemical change is a change in matter that produces a new substance with different properties from the original.
Rust is iron oxide: iron + oxygen = rust
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Chemical Changes
A compound is a chemical combination of two or more substances.
Sugar is composed of the elements: carbon, hydrogen and oxygen
C12H22O11
Carbonic acid is also composed of the elements: carbon, hydrogen and oxygen
DO NOW
Which of the following graphs shows how the temperatures of the two cups of water most likely changed over 30 minutes?
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Temperature and Heat:Energy
Energy = the ability to move matter• Any moving object has energy– Molecules– Cars– Balls– Bikes– A swung baseball bat
Moving Molecules Produce Heat
• Molecules move • The average kinetic
energy determines how hot or cold a material is…its temperature.
.
Two Kinds of energy:Kinetic and Potential
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Kinetic Energy
• The energy of any moving object– A speeding roller coaster dropping down a hill.
Potential Energy
• Energy stored in an object or material. – Moving an object upwards against gravity.• A roller coaster climbing up to the next drop.
Potential Energy and Kinetic Energy
Heat
• Energy flows between two objects because they have different temperatures.
• Heat is a form of energy.• Energy will flow from a
hotter object to a cooler one and continue to flow until the objects are the same temperature.
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Radiation, Conduction and Convection
• Radiation– The transfer of energy by
electromagnetic waves.
• Conduction– The movement of energy
through direct contact.
• Convection– The transfer of energy by
the flow of a liquid or gas.
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Electricity and Magnetism
Static Electricity: when electrons move from one place to another and cause a buildup of an electrical charge
.
Electricity and Magnetism
Conductor: A material through which electricity flows easily -
metals, water, humans
Insulator: A material through which heat or electricity does not flow easily –
rubber, wood, plastic
Electricity and Magnetism
Open circuit: a circuit that has a gap, so electrons cannot flow.
Close circuit: a circuit that has no gap, so electrons can flow.
Electricity and Magnetism Magnet: any object that attracts or repels other
magnets, and also attracts metal objects made of iron, cobalt or nickel
.
Speed and Distance
Average speed = distance ÷ time
3000 m ÷ 15 min = 200m/min
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