Transcript ES 2nd Six Weeks Review Gamex

1. These gases were more than likely a part of Earth’s
first atmosphere, because of their relative
abundance in the universe, and their distribution
during the solar nebula which formed our solar
system.
ANS: hydrogen and helium
2. One thing scientists agree on is that there was no
____ in Earth’s second atmosphere.
ANS: free oxygen
3. In the balanced chemical equation for
photosynthesis below, what reactant and product
are hidden beneath the blue boxes?
4. Today, Earth’s atmosphere has a much greater
amount of free oxygen. This is largely due to what
process?
ANS: photosynthesis…first of cyanobacteria, and then of the
more advanced plants that evolved later.
5. What was likely the origin of Earth’s second
atmosphere?
ANS: gases emitted from volcanoes (volcanic outgassing)
6. Describe ONE possible origin for Earth’s oceans.
ANS: Cometary delivery; probably some but not all, due to the
fact that long period comets contain heavy water and the ocean
has mostly regular water. Volcanic outgassing of water vapor,
and when cool enough, water condensed and precipitated
collecting in low areas, forming oceans over the eons.
7. How did our oceans get salty?
ANS: Precipitation hitting the Earth’s surface, weathering and
eroding the rocks, and carrying those minerals (mostly salt) into
the ocean, making it salty.
Use the word bank below to answer the following
questions.
Atmosphere (A) Hydrosphere (H)
Geosphere (G)
Biosphere (B)
8. Contains the Earth’s Oceans, rivers and streams H
9. Protects Earth from solar radiation
10. Contains Ozone (O3) A
11. Crust to core, abiotic G
12. Has trees and paramecium B
13. Includes tectonic plates G
A
14. The oxygen/carbon cycles on Earth
were made possible by what tiny
organisms that first were able to convert
CO2 into O2 through photosynthesis?
ANS: Cyanobacteria/Blue-green algae
15. Why did Earth’s second volcanic
atmosphere finally change?
ANS: Photosynthesis began to use up the CO2,
and produce O2, and nitrogen (N2) is highly
inactive and is allowed to accumulate.
16. Judging from the image below, showing the
Atlantic Ocean basin, what is happening to the
size of that ocean due to convection currents in
the mantle?
of Gases
from (wider)
Hawaiian Volcano
ANS:Analysis
It is getting
larger
Gas
Amount
79%
2O (steam)
17. WhatHCO
protective
molecule
forms
12%
2
SO2
6.5%
N2
1.5%
from harmful
UV radiation?
H2, CO, Cl2, and Ar
trace
in our
Stratosphere and serves to shield the biosphere
ANS: ozone (O3)
18. What are the two main gases emitted in a
volcano?
ANS: H2O and CO2
19. Describe the force that moves tectonic plates
around on the surface of the Earth.
ANS: The force is created by heated convection currents in the mantle
20. What likely happened to Earth’s first
hydrogen/helium atmosphere?
ANS: It was blown out into space by solar wind and debris, due
to the fact that Earth had no magnetosphere yet.
21. Why did methanogens (early anaerobes) likely
become extinct all those years ago, and what was
the name of this extinction event?
ANS: due to increasing levels of O2 in the atmosphere created by
cyanobacteria. The GOE, Great Oxidation Event.
22. Seasonal variations in atmospheric oxygen levels
led to interesting rock formations which are
considered evidence of free oxygen in Earth’s 3rd
atmosphere. These rock formations are known as
ANS: BIF, and red beds
23. When radioactive parents decay, or are reduced
exponentially over time, they change into?
ANS: Daughters
24. When viewing the geologic time-scale (such as
depicted here), are the older geologic events located
at the top or the bottom?
ANS: At the bottom
25. What is an unconformity?
ANS: A gap in the geologic record
Use the following phrases/terms to answer the next
questions.
Superposition (S)
Original Horizontality (OH)
Cross-Cutting Relationships (CCR)
Inclusions (I)
26. Particles of granite can be found in sandstone. Granite is
older. ANS: I
27. Layers of sediment are generally deposited in a parallel,
horizontal manner, due to gravity. ANS: OH
28. Each successive layer is younger than the one
beneath it. ANS: S
29. What percentage of parent ALWAYS decays with
each half-life?
ANS: 50%
30. When two protons bound to two neutrons are
“kicked” out of the nucleus, what type of radioactive
decay has occurred?
ANS: Alpha Decay
31. How does beta decay differ from alpha decay?
ANS: In beta decay, a neutron turns into a proton, and
emits an electron (beta particle)
32. Describe ONE limitation of radiometric dating.
ANS: You have to have measureable amounts of each parent,
and daughter; Specimen is destroyed in process; rarely found in
sedimentary rocks…etc.
33. Why might a geologist find studying the Grand
Canyon interesting?
ANS: Millions of years of Earth’s history can be read in the rocks.
Earth processes are recorded in the rock layers there.
34. When lithified sediments have been disrupted
and tilted sideways, and then overlain by horizontal
sediments (such as above), it is evidence of what type
of unconformity?
ANS: Angular unconformity
35. When the unconformity involves an eroded
underlying igneous or metamorphic layer, with
sediment above what type is it?
ANS: Nonconformity
36. Using the index fossils in the diagram below, what
do you know about layers A, and B, for sure?
ANS: They were both laid down at the same time
37. What is the process by which atomic nuclei
spontaneously break-down over time?
ANS: Radioactive decay, or radioactivity
A
B
38. What is a half-life?
ANS: The time period it takes for ½ of the parent isotope to
break down into the daughter isotope.
39. A rock sample has 64 atoms of a radioactive
element. If its half-life is 15 seconds, how many atoms
of parent isotope are left after 45 seconds, and how
many daughters have evolved?
ANS: 8 atoms of parent; 56 of daughter
40. Using the diagram above, put the layers in order
from most recent, to oldest.
ANS: D; A; C; B; E
41. Proportionally, how much of the original parent
isotope will remain after 2 half-lives?
ANS: ¼
42. The most recent era on the geologic time-scale,
which includes today, is known as what?
ANS: Cenozoic
43. The accelerated evolutionary event of
multicellular life occurred during the Paleozoic era
and was called…
ANS: The Cambrian Explosion
44. The law of superposition states that each
successive layer, is _(older/younger)__ than the layer
below it.
ANS: younger