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Unit 3

Lesson 1: Earth’s Support of Lifeand

Lesson 2: Natural Resources

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Living It Up• What do living things need to survive?

1. Air to breathe

2. Water to drink

3. Energy from food

4. Habitat – a place to live and provide protection.

• The Earth and Sun interact to support life on Earth.• Plants use the sun’s energy to make their own food

through photosynthesis.• Photosynthesis – Plants take in sunlight energy + CO2 +

water and they give off oxygen + sugar (food).

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Photosynthesis

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Water, water Everywhere• How did earth get its water?

• Earth formed from molten materials like, Iron, Nickel, and Silica.

• These materials separated into layers and began to cool.• As Earth cooled it released steam and other gases into

the atmosphere.• The steam formed clouds, and water fell to Earth as

rain.• This formed the oceans.• Some also came from icy comets and meteors from

space.

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Formation of Water

About 71% of earth’s surface is now covered with water.

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Security blanket• Atmosphere – a mixture of gases that surround a

planet, moon, or other space object.• Most space objects have atmospheres.• Mercury and the moon do not have atmospheres

because gravity is much weaker and is not strong enough to hold the gases in place.

• Carbon dioxide and oxygen support most forms of life on Earth.

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Security blanket• Gases Insulate Earth

• Solar radiation passes through the atmosphere and is absorbed by earth’s surface.

• Radiation energy moves into the atmosphere.• Greenhouse Effect – radiation energy is absorbed and re-

radiated by atmospheric gases. Traps the solar heat!• The greenhouse effect keeps Earth warmer than it would

be if earth had no atmosphere.

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Security blanket• The Ozone Layer Protects Earth

• Ultraviolet radiation – A type of solar radiation that can harm life.• It is harmful; it can damage the genetic make-up (genes or DNA)

in organisms.• Earth’s ozone layer blocks most UV Radiation.• Ozone – a molecule that is made up of 3 oxygen atoms – makes

up the ozone layer.• It helps reflect UV Radiation

• Some human made chemicals have damaged the ozone layer.• Like CFC (chloro fluoro carbons)

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Unit 3: Lesson 2Natural Resources

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It’s Only Natural• What are Natural resources?

• Any natural material that is used by humans.• Include: air, soil, minerals, water, oil, plants, animals, wind.• All energy comes from the sun – it is then transferred into

different forms.• Earth’s resources produce products that make people’s

lives more convenient.• There are 2 categories:

1. Renewable

2. Nonrenewable

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Renewable Resources• Renewable resources – a natural resource that can

be replaced at the same rate at which it is consumed.• Can be replaced in a short period of time.• Solar energy• Air• Water• Trees (wood/paper) and crops –

sometimes trees are cut

down faster than they can

regrow.

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Nonrenewable Resources• Nonrenewable Resource – A resource that forms

much more slowly than it is consumed.• Takes millions of years to regenerate.• Include fossil fuels• Fossil fuels – nonrenewable; formed from the buried

remains of plants and animals that lived long ago.• Examples include: Coal, oil, and natural gas.• The original source of all energy comes from the sun.

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A Material World• Material Resources – are natural resources that are

used to make objects, food, or drinks.• Can be renewable or nonrenewable

To Make Food or Drink- Wheat- Corn- Milk- Cheese- Eggs- Meat from animals- Water

To Make Objects- Steel- Plastic- Rubber- Glass- Leather- Iron- Oil- Sand

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Change It Up• How do we use energy resources?

• Energy resources – are natural resources that are used to generate energy.

• 2 types1. Potential energy – stored energy

- Examples include food, gasoline, any non moving object.

2. Kinetic energy – energy of movement- Anything in motion.

• Potential energy is converted into Kinetic energy

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Law of Conservation of Energy• Energy cannot be created or destroyed but it can

be transferred from one form to another.• Electrical energy to heat

• Electrical energy to light and sound energy

• Electrical energy to kinetic energy