Transcript 7thGrade_BR_January_2012

1/2/12
Bell Ringer – page 72
Fossils of the same plants and animals are found on
continents that are on different sides of the
Atlantic Ocean. Which of these statements does this
observation support?
A. These animals and plants crossed the Atlantic Ocean.
B. The Atlantic Ocean was once a large body of
freshwater.
C. The continents that are now on opposite sides of the
Atlantic Ocean once formed a single landmass.
D. The continents that are now on opposites sides of
the Atlantic Ocean have the same kinds of animals
and plants today.
1/3/12
Bell Ringer – page 72
Which of these choices is an example of the
way a geologist would use relative dating?
A. determining the minerals that make up rocks
B. placing rock samples in order of oldest to
youngest
C. classifying rocks as igneous, sedimentary, or
metamorphic
D. using radioactive isotopes to determine the
exact age of rock samples
1/4/12
Bell Ringer – page 74
The picture shows the rock layers in one part of
the Grand Canyon. What is the order of rock
layers, from oldest to youngest?
A. 1, 2, 3, 4
B. 2, 1, 4, 3
C. 3, 4, 1, 2
D. 4, 3, 2, 1
1/5/12
Bell Ringer – page 74
Igneous rock cuts through three layers
of sedimentary rock. Which rock is the
youngest?
A. the igneous rock
B. the top layer of sedimentary rock
C. the middle layer of sedimentary rock
D. the bottom layer of sedimentary rock
1/9/12
Bell Ringer – page 76
Which property of fossils allows scientists to
determine the relative ages of rock layers?
A. Fossils form from the remains of living
organisms.
B. Fossils are usually found only in sedimentary
rock.
C. Fossils can be analyzed to determine their
exact ages.
D. Fossils show how earlier organisms evolved
into newer organisms.
1/10/12
Bell Ringer – page 76
A scientist wants to make a geologic column of
rock layers from different parts of a state. How
will the scientist do this?
A. The scientist will organize the layers by comparing
the fossils and types of rocks.
B. The scientist will measure the exact ages of the
rocks found in each part of the state.
C. The scientists will look at the geologic features in
each area and make models of them.
D. The scientist cannot make a geologic column from
rock layers from different places.
1/11/12
Bell Ringer – page 78
What is the approximate age of
Earth?
A. 4.5 billion years
B. 5.6 billion years
C. 6.6 billion years
D. 7.6 billion years
1/12/12
Bell Ringer – page 78
The age of objects can be determined by a
method known as radiometric dating. What does
this kind of dating use to determine the age of
objects?
A. fossils
B. isotopes
C. tree rings
D. rock layers
1/18/12
Bell Ringer – page 80
During one kind of radioactive decay,
potassium-40 breaks down into argon40. Which of the following can be
determined about argon-40?
A. Argon-40 is the parent isotope.
B. Potassium-40 is the daughter isotope.
C. It is less stable than potassium-40.
D. It is more stable than potassium-40.
1/19/12
Bell Ringer – page 80
The age of a rock sample can be determined by
finding the amount of a parent isotope that has
changed into a daughter isotope within the
sample. Which property of radioactive decay
allows the age of the rock to be determined in
years?
A. releases energy
B. releases particles
C. happens in all rocks
D. happens at a set rate
1/23/12
Bell Ringer – page 82
The table below shows the half-lives of three
isotopes.
Which statement best explains why these
isotopes can be used to date rocks?
A. They are all rare isotopes.
B. They all decay at set rates.
C. They are all large molecules.
D. They are all stable over time.
1/24/12
Bell Ringer – page 82
Florida was once part of Gondwanaland, which
was a supercontinent that later divided into
Africa and South America. What is the name of
the process that takes place when a
supercontinent breaks apart?
A. continental rise
B. continental drift
C. abyssal plain
D. continental divide
1/25/12
Bell Ringer – page 84
Leon wants to determine the age of igneous
rock by comparing the amount of potassium40 to the amount of argon-40 present in rock
samples. What is the correct term for this
method of determining the age of an object?
A. isotope dating
B. relative dating
C. radiometric dating
D. radiocarbon dating
1/26/12
Bell Ringer – page 84
Hot, melted rock is injected into several rock
layers. Over time, the rock cools. It becomes
solid and cuts through the surrounding rock.
Which choice explains how the age of this rock
relates to the surrounding rock?
A. the geologic record
B. the law of superposition
C. the principle of unconformity
D. the law of crosscutting relationships
1/30/12
Bell Ringer – page 86
In 1897, a British scientist proposed that the
Earth was between 20 and 400 million years old.
Today, scientists have proposed a different age
for Earth. How old do they think the Earth is?
A. 40 billion years old
B. 20 billion years old
C. 4.6 billion years old
D. 4.6 million years old
1/31/12
Bell Ringer – page 86
Julia has two samples of rocks for which she
wants to find the ages. She has a sample of
sandstone and a sample of granite. Which
statement explains why she can date only the
granite?
A. The granite is older.
B. The granite is igneous.
C. The granite is younger.
D. The granite is sedimentary.
2/1/12
Bell Ringer – page 88
The figure below shows one type of physical
evidence that scientists use to understand
how Earth’s climate has changed in the past.
What type of physical evidence is shown in
this figure?
A. cast
B. mold
C. ice core
D. tree rings
2/2/12
Bell Ringer – page 88
Sandra is making a poster of Earth’s
major geologic epochs. She wants to
include a timeline on her poster. Which
date should Sandra use as the beginning
of her timeline?
A. 700 million years ago
B. 3 billion years ago
C. 4.5 billion years ago
D. 12 billion years ago