Transcript Science Chapter Review Book: [Book Name]

Teacher: Mr. Carl
Objective
 At the end of this lesson, you will be able to:
 Explain how rocks and fossils are used to understand the
age and geological history of the Earth.
Chapter Terminology:
 Fossils
 Relative Age
 Radioactive Dating
 Geologic Time Scale
 Mass Extinction
 EXIT
Fossils
 Definition: The preserved remains or traces of living
things.
Fossils
 Explanation: For a fossil to form,
the remains or traces of an
organism must be protected
from decay. Then one of several
processes may cause a fossil to form. Fossils
found in rock include petrified fossils, molds and
casts, carbon films, and trace fossils. Other fossils
form when the remains of organisms are
preserved in substances such as tar, amber, or ice.
Fossils
 Example: How are Fossils Made? (click on video to
start – it may take a few moments to start)
Quiz Time!
 Question: What is a fossil?
 A: Old bones dug up from the Earth
 B: Sediment that hardens into rock from years of
pressure and heat being applied
 C: The preserved remains or traces of living things.
 D: Any dead animal or plant is a fossil
Congratulations!
 You are correct. Lets move on…
Sorry… selection not correct.
 Lets try this again. Would you like to:
 Review (or)
 Try the quiz again
Relative Age
 Definition: The relative age
of a rock is its age compared
to the ages of other rocks.
Relative Age
 Explanation: When you look at a rock containing a
fossil, your first questions may be, “How old is it?” You
have probably used the idea of relative age when
comparing your age with someone else’s age. For
example, if you say that you are older than your
brother but younger than your sister, you are
describing your relative age.
Relative Age
 Click on this video explaining relative age…
Quiz Time!
 Question: What is Relative Age?
 A: Relative age is its age compared to the ages of other
rocks.
 B: The age of my relatives
 C: Relative age is the number of years since the rock
formed.
 D: In horizontal sedimentary rock layers, the oldest
layer is at the bottom and each higher layer is younger
than the layers below it.
Congratulations!
 You are correct. Lets move on…
Sorry… selection not correct.
 Lets try this again. Would you like to:
 Review (or)
 Try the quiz again
Radioactive Dating
 Definition: measurement of the amount of radioactive
material (usually carbon 14) that an object contains;
can be used to estimate the age of the object
Radioactive Dating
 Explanation: Geologists use radioactive dating to
determine the absolute ages of rocks. In radioactive
dating, scientists first determine the amount of a
radioactive element in a rock. Then they compare that
amount with the amount of the stable element into
which the radioactive element decays.
Radioactive Dating
Click on the video on Radioactive Dating…
Quiz Time!
 Question: What is Radioactive Dating?
 A: The process of elements breaking down, or decaying
by releasing particles and energy
 B: The rate of decay of each radioactive element
 C: The process used to achieve a relative date of a rock.
 D: Scientists first determine the amount of a radioactive
element in a rock, then they compare that amount with
the amount of the stable element into which the
radioactive element decays.
Yeay!
 You are correct. Lets go to the next term…
Sorry… selection not correct.
 Lets try this again. Would you like to:
 Review (or)
 Try the quiz again
Geologic Time Scale
 Definition: A record of the geologic events and life
forms in Earth’s history
Geologic Time Scale
 Explanation: Scientists first developed the geologic
time scale by studying rock layers and index fossils
worldwide. With this information, scientists placed
Earth’s rocks in order by relative age. Later, radioactive
dating helped determine the absolute age of the
divisions on the geologic time scale. As geologists
studied the fossil record, they found major changes in
the life forms at different times. They used these
changes to mark where one unit of geologic time ends
and the next begins. Therefore the divisions of the
geologic time scale depend on events in the history of
life on Earth.
Geologic Time Scales
 Click on video to explain Geologic Time Scales
Quiz Time!
 Question: What is a Geologic Time Scale?
 A: It consists of only three Eras: Mesozoic, Paleozoic
and Precambrian.
 B: The record of the life forms and geologic events in
Earth’s history.
 C: The time frame of the past 544 million years
 D: The time frame when life existed on Earth
Yippy!
 You are correct. Lets move on…
Sorry… selection not correct.
 Lets try this again. Would you like to:
 Review (or)
 Try the quiz again
Mass Extinction
 Definition: When many types of living things become
extinct at the same time.
Mass Extinction
 Explanation: The mass extinction at the end of the
Paleozoic affected both plants and animals, on land
and in the seas. Scientists do not know what caused
the mass extinction, but as much as 95 percent of the
life in the oceans disappeared.
Mass Extinction
 Example: Dinosaurs are an example of a mass
extinction (click on video to start).
Quiz Time!
 Question: What is Mass Extinction?
 A: A time when all of one type of living thing becomes
extinct at the same time.
 B: When all land animals die at the same time.
 C: A time when many types of living things become
extinct at the same time.
 D: Any time a species dies off and becomes extinct.
What a Discovery!
 You are correct. Lets move on…
Sorry… selection not correct.
 Lets try this again. Would you like to:
 Review (or)
 Try the quiz again
Credits
 Absolute VS Relative Ages 2011. TaterChron1. Web. 27 Feb. 2012.






<http://www.youtube.com/watch?v=JNOmpXo2xlU>.
Carl, Carrie. Voice Narration. Web. 27 Feb. 2012.
Dinosaur Extinction. 2009. Sheppard Software Com. Web. 27 Feb. 2012.
<http://www.youtube.com/watch?v=YQoYF9iRmEs>.
Geologic “Eras”, Animated 2009. Pellosborn. Web. 27 Feb. 2012.
<http://www.youtube.com/watch?v=SY3MZ_wNFW8&feature=related
>.
How Fossils Are Formed 2009. Sheppard Software Com. Web. 27 Feb.
2012.
<http://www.youtube.com/watch?NR=1&feature=endscreen&v=TVwP
LWOo9TE>.
Microsoft Office 2007 clipart, movie and sounds
Radiometric Dating Age of Earth 2007. Acorvettes. Web. 27 Feb. 2012.
<http://www.youtube.com/watch?v=6SxzfZ8bRO4>.
EXIT