WorksheetsDiscovering Earth's History
Total questions: 18
Worksheet time: 9mins
The largest expanse of time on the geologic time scale is the ____________.
eon
epoch
era
period
When did the Phanerzoic eon begin?
2.0 million yesrs ago
540 million years ago
10.1 million years ago
20.5 million years ago
Radioactivity is produced when unstable nuclei ___________.
bond
break apart
beome cooler
expand
Rocks record geological events and _________________
life forms of the present
life forms of the past
astronomical milestones of the past
Earth's circumference and diameter in the past
For what purpose do geologists use relative dating?
to determine which rock layer in a canyon wall formed first
to find the age of a rock layer
a rock's composition has changed
to identify past life forms that once lived in a rock layer
In general, The law of superposition states each rock layer is___________.
about the same age
older than the one above it
older than the one below it
thicker than the one above it
What are fossils?
the oldest layer of rock in a region
the remains or traces of an organism preserved from the geologic past
living creatures
objects people left behind in the past
Index fossils allow geologists to
match rocks of the same age in different regions
determine the exact age of the rocks
identify organisms that did not leave fissil evidence behind
determine why some organism became extinct
Which two substances are involved in carbon -14 dating?
carbon -12 and carbon -10
carbon -14 and uranium -238
lead-206 and carbon - 14
carbon-14 and carbon-12
Which of the following is important if an organism is to become a fossil?
soft parts and slow burial
rapid burial and hard parts
rapid burial and soft parts
hard parts and slow burial.
True or False
An extinct organism is one that is still found on earth.
True
False
True or False
The Precambrian represents a much longer part of Earth's history than the Phanerozoic.
True
False
The eon called the __________________ began about 540 million years ago.
Proterozoic
Phanerozoic
Hadean
The longest unit of geologic time is____________.
era
eon
epoch
period
The shortest unit of geologic time is_____________________.
eon
ers
period
epoch
The process by which unstable nuclei spontaneously decay is known as________________.
radioactivity
fire starter
stable isotope
old age
What decays first during radioactive decay?
parent element
stable isotope
stable daughter product
superman
True or False
A radioactive isotope decays at a varying rate from the time it forms.
True
False
