Name ______________________ Date of Assessment Thursday, March 26
Science Review
Chapter 6- (Lesson 3- Fossils and Energy) and (Lesson 4- Air and Water)
Lesson 3 - Fossils and Energy
I. What are fossil fuels? pgs. 174 and 175
A. Fossils:
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are remains or traces of something that lived long ago
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formed by the remains of dead organisms covered with sediment
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used by scientists to learn about the past; for example present living animals
in warm climate have a certain trait, if a fossil with the same trait is found in
Antarctica this tells us that Antarctica was once warm
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usually found in sedimentary rocks
* Fossils are usually found in sedimentary rock. When an organism dies, it may
be
covered by sediment. The sediment hardens over time and forms a fossil.
Igneous rocks form from the cooling of magma. Metamorphic rocks form from
rocks under great heat and pressure. Any fossils contained in these rocks
would
be destroyed by the heat and pressure
A.
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Fossil Fuel:
a fuel formed from the remains of ancient plants and animals
source of energy
example of fossils fuels- coal, oil, and natural gas
C. Coal is formed by:
Dead organisms in a swamp form peat --> peat is covered with layers of sediment ->
pressure hardens peat into coal
peat- dead organisms that are buried in Earth
D. Oil and gas formed by:
Dead organisms fall to the ocean floor ---> the dead organisms are buried in
sediment ---> pressure forms oil and gas
I. How old are fossils and fossil fuels? pgs. 176 and 177
A. Law of superposition:
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a layer of rock is usually older than the layer above it
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a layer of rock is younger than the layer below it
A. Elements:
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are used by scientists to determine how old the rock is in order to find the age of
the fossil
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rocks contain at least one element
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some elements change into other elements over time
I. Half-time:
• the time it takes for half the element to be changed into another element
I.
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I.
Eras:
scientists use the ages of fossils to tell the history of Earth
scientists divide Earth’s history into eras
an era is measured in millions of years
How are fossil fuels used? pgs. 178 and 179
A. nonrenewable resources:
• cannot be replaced or reused easily
• fossil fuels take millions of years to form
• if we are not careful, we may use them up
• once they are used, they are gone forever
• examples or nonrenewable resources- coal, oil, and natural gas
A. renewable resources:
• can be replaced or used again and again
• examples of renewable resources- wind, moving water, and sunlight
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living things can be renewable resources
example of living renewable resources- fish and trees
I. How can wind, water, and the sun make energy? pgs. 180 and 181
A. energy from wind:
• wind energy does not pollute the air
• wind energy can be used only where wind blows all the time
• example of wind energy- wind blows---> turns blades ---> blades are attached to a
generator ---> generator moves ---> creates electricity
generator- a machine that converts one form of energy into another, especially
mechanical energy into electrical energy
A. energy from moving water:
• example of moving water energy- running or falling water turns a wheel ---> the
wheel moves an axle or rod ---> the axle can be connected to some machines to
do work ---> creates electricity
• examples of machines an axle is connected to are usually in a hydroelectric plant
• prefix hydro- in the word hydroelectric means “water”; running water or falling water
spins a generator
• hydroelectric plants do not pollute air or water
• hydroelectric can be used only where there is moving water
I. solar energy:
• sunlight falls on solar cells ---> cells capture the Sun’s light energy---> they turn this
energy into electricity
• solar energy does not cause pollution
I. What are other sources of alternative energy? pg. 182
A. nuclear energy• energy produced when atoms of elements change into atoms of other elements
• steam used to move parts of an electric generator
A. geothermal energy• energy produced by heat from inside the Earth
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causes hot springs
hot springs can be piped to machines that move generator parts
prefix geo- in the word geothermal means “earth”; thermal means “relating to heat”
I. biomass energy• energy source that comes from living things
• prefix bio- in the word biomass means life or living organisms
• examples of biomass- wood, animal wastes, and cornstalks
VI. How can we conserve energy? pg. 183
A. Ways to conserve energy• turn off lights when you leave a room
• turn off electric equipment when not using them
• use water conserving shower heads and take shorter showers
• turn water off when not using it
• carpool or use public transportation
• turn down the heat or air conditioning when you are not home; insulate windows and
doors to prevent heat loss
Lesson 4- Air and Water
I. What are sources of fresh water? pgs.184 and 185
A. running water• many cities built next to rivers or streams because the running water provides fresh
water for homes, farms and businesses
A.
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standing waterreservoir- a storage area built to store fresh water
reservoir created by building a dam across a river
water stored behind dam and released when needed
C. groundwater• water seeps into ground through aquifers
• an aquifer is an underground layer of rock or soil; it has holes in it and can absorb
water
• as water seeps through an aquifer, it eventually reaches a layer of rock that does not
absorb water
• freshwater builds on top of this rock
• groundwater can be reached by people when it is close to the surface by drilling or
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digging into the ground
groundwater is pumped through a well and provides water for human use
II. How do we clean, conserve, and protect water? pgs. 188 and 189
A. Water treatment plant•
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coagulation- sticky particles are added to water to attract dirt
sedimentation- dirt and sticky particles fall to the bottom of the tank
filtration- water passes through filters and removes any bits of soil
disinfection- chemicals are added to kill bacteria
clean water stored until sent out for community use
A. Conserve water by:
• using water conserving shower heads
• run appliances such as a dishwasher or washing machine only when they are full
• fixing leaking pipes or faucets
• grow plants that do not require a lot of water
I. In 1974 Congress passed the Safe Drinking Water Act which set rules the
communities must follow to keep drinking water clean and safe
I. In 1977 Congress passed the Clean Water Act, an act that makes it illegal to pollute
water
I. How do we use and pollute air? pg. 190
A. Some sources of air pollution are:
• smoke from vehicles
• construction sites
• mines
• plowed fields
• aerosol cans
• air conditioners
A. Ozone layer• layer that protects living things from the Sun’s harmful rays
I. Ozone hole• there are holes in the ozone layer
• these holes are dangerous because they allow harmful radiation from the Sun to
reach the Earth’s surface
smog- air pollution caused by particles that are produced when fossils are burned;
irritates eyes and can make breathing difficult
I. How do we protect air? pg. 191
A. In 1963 Congress passed the Clean Air Act which states many pollutants are illegal.
Some pollutants must be filtered to remove any harmful chemicals before they
reach
the air.
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aerosol cans are no longer allowed to use chemicals that destroys the ozone
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factories must trap the pollutants found in their smokestacks
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vehicles must have devices that will limit gas from exhaust pipes