Test Review Activity 1 & 2
Open Response #1
• Describe the nebular theory of the formation
of our solar system ON YOUR ANSWER SHEET.
Use and underline these key terms in your
writing (nebula, gravity, planetesimals
(chunks), nuclear fusion, swirling/rotation,
star/sun, mass/matter )
• Go to reading guide Solar System entry and
look at the sequence of events in the nebular
theory. Turn it into a paragraph. Define
vocabulary terms as you use them.
• DO NOT simply list the key terms without
tying them together into an explanation.
Example Answer
• Restate question/ topic sentence: The Nebular theory describes
the formation of the solar system.
• First a supernova explodes and a cloud of gas and dust from the
blown up star is formed – a nebula. Gravity pulls clumps of matter
together and they form into chunks and grow bigger. As gravity
causes the nebula to contract most of the mass is concentrated in
the center and the cloud begins to spin or rotate. The clump of
material in the center of the cloud becomes very hot as gravity
continues to pull it inward. Eventually, nuclear fusion begins in the
center of the cloud and becomes the sun. Meanwhile, in the outer
parts of the cloud, clumps of matter stick together and form larger
bodies called planetesimals that will become the planets.
• Conclusion: The solar system has formed due to gravity and the
planets revolve around the central sun.
#2 Venn Diagram Inner VS Outer
(Go to Reading Guide Solar System Entry)
Inner : Smaller, warmer, rocky, molten metal cores,
closer to sun, fewer moons, no rings, denser, shorter
years, brighter
Outer: larger, colder, gas /liquid hydrogen and methane,
farther from sun, more moons, many rings, less dense,
longer years, dimmer
Both: same age, from same nebula, revolve around sun,
rotate on axis, spherical
#3 Hours Per Day Over Time Data
A. The title of this graph is inappropriate. What
would be the best title for this graph?
• Titles had to refer to both axes: Changes in day
length(days per year) over 600 million years
(geologic time).
B. What was the number of days in an Earth Year
550 million years ago?
• 415-420 days per year (less points for 400-410 or
no unit)
Cite evidence from table or graph!!
Time Period
Precambrian
Cambrian
Ordovician
Silurian
Devonian
Mississippian
Pennsylvanian
Permian
Triassic
Jurassic
Cretaceous
Present
Date
(millions
years
ago)
600
500
425
405
345
310
280
230
180
135
65
0
Length of
Year (days)
424
412
404
402
396
393
390
385
381
377
371
365.25
C. State how the earth year has
changed through time. Cite 2 pieces of
specific evidence to support your claim.
Topic sentence:
The number of days in a year is
decreasing over time.
Cite 2 pieces of evidence: For example,
600 mya length of year was 424 days
290 million years later, at 310 mya the
length of the year had decreased to 393
days per year. A decrease of 31 days in
290 million years a rate of 0.1 day every
million years.
What do you predict will happen to the length of an
earth year in 100 million years from now? Why do you
think that? (Reading Guide Moon Entry)
• Extrapolate from the slope of the graph –
approximately 350 days per year
• You determined this by extending the line of
the graph using a best fit line
• You know that the Earth is slowing because of
tidal friction caused by the moon’s pull on the
Earth and its oceans
y = 0.0961x + 363.87
R² = 0.996
Day Length Graph
440
400
380
360
340
320
700
600
500
400
300
Years before present (millions of years ago)
200
100
0
Number of Days in an Earth Year
420
#4 Scale Model of Asteroid Distance
• What is a scale model and why are they useful?
• Complete the table ON YOUR ANSWER SHEET to
determine the distance from the sun of the very
largest asteroid, Ceres – at 448,000,000 km–
using the three different scale models in the chart
provided. You may use a calculator (no sharing!).
• If you had to actually place this asteroid on the
rope model of our solar system, where – relative
to the planets - would the asteroid be placed?
Support your answer with specific evidence
(numbers!) from your Activity 1.
4. A. Define Scale Model
(Go to scale model activity entry)
• General question not specific to our model
• Don’t define it using its own name
Ex: Scale is a particular type of model that is
proportional to the actual object that it is
representing.
2nd part to question- use
Ex. Shows things too big or small to see for
ourselves.
4. B & C Scale Calculations
• Actual size divided by the scale
448,000,000 divided by 150,000,000 = 2.986
• Place the asteroid belt between Mars and
Jupiter this is relative to the planets
(explain the distance you calculated according to
the scale)