ESS 101 EXAM WITH CORRECT
QUESTIONS AND ANSWERS
usr
[COMPANY NAME] [Company address]
,1. nebular hypothesis Answer: 1. supernova and formation of primordial dust cloud
2. condensation of primordial dust forms disk shaped nebular cloud rotating counter-clockwise.
3. proto sun and planets begin to form
4. accretion of planetesimals and ditterentiation of planets and moons (4-6 billion years ago).
5. existing solar system takes shape.
2. Evidence of nebular hypotheses Answer: 1. Planets and moons revolve in a counter-
clockwise direction (not random)
2. almost all planets and moons rotate on their axis in a counter-clockwise direction.
3. planetary orbits are aligned along the suns equatorial plane (not randomly organized)
4. observations from Hubble telescope and radio astronomy indicate that other planetary systems are
forming from condensed nebular dust.
3. Terrestrial Planets Answer: Close to the sun, dense, small/rocky, silicate minerals, metallic
cores
Twelve earths would fit across the diameter of Jupiter.
4. Jovian Planets Answer: Far from the sun, low density, large, gaseous (hydrogen, methane)
5. Why does the earth and terrestrial planets have so little molecular
hydrogen comprising their respective atmosphere, yet the primordial
dust cloud was mostly comprised of hydrogen gas? Answer: Hydrogen gas and
helium gas escapes to space when put in our atmosphere.
Jupiter, saturn, and neptune maintain molecular hydrogen gas in the atmosphere because they have high
density.
6. Differentiated Earth Answer: 1. Iron Nickel Core
(outer core liquid) (inner core solid)
2. Fe-Mg silicate mantle
3. Fe-Mg-Al Silicate Crust (Ocean and Continental)
4. Oceans
5. atmosphere
7. How is the earth compositionally zoned? Answer: Along a density gradient
8. How did the earth become compositionally zoned? Answer: 1. Accretion of
planetesimals
2. initial heating due to kinetic energy of colliding planetesimals and compressional heating.
3. additional heating from radioactive decay.
,4. iron catastrophe Answer: melting temp of iron reached and dense iron nickel sink to core and lighter
materials are displaced outwards (including silicate rock of mantle and crust, ocean waters and
atmospheric gases)
, 5. earth becomes compositionally zoned based on density (densest iron nickel in core-least dense
materials comprise the atmosphere) 500 mil yrs after the initial accretion process.
6. convective overturn in asthenosphere, mantle and outer core still occur today.
9. Why did the earth heat up and then rapidly cool during the
differentiation process? Answer: When earth was solid-heat gain was greater than the heat
lost to space. This means that the internal temperature rises until it exceeded the melting temp of
oxygen and nitrogen until exceeded iron nickel catastrophe. Earth is completely molten and then
compositionally zoned.
When earth was liquid- convection-hot gas rises , after it became molten, the earth rapidly cooled ott and
solidified.
10. Why does earth possess little evidence of its early accretion
history? Answer: Because of weathering, plate tectonics, moon has no atmosphere and
biosphere.
11. Emissions from degassing of the earth during its differentiation.
Answer: h2o, co2, h2, he, n2
12. Where did molecular H and He escape to? Answer: space
13. When did oxygenation of the atmosphere occur? Answer: later following
evolution of marine algae and plants that use photosynthesis to convert co2 to o2 as a part of
their life processes.
14. What layers of the earth can be directly observed? Answer: crust and
uppermost mantle.
15. Evidence of initial composition of the solid earth based on
meteorite studies. There are two major classes of meteorites that
dominate collected samples. Carbon based meteorites are much
rarer, but indicate that the prescursor of life was present early on. Answer:
1. Metallic meteorites (iron nickel density 9.0-10 gm/cm3)
2. chondritic meteorites Answer: Fe-Mg silicate, rocky, density is 3.0-3.3)
3. carbonaceous chondrites (rare)
16. What is earths average density? Answer: 5.5 g/cm3
17. How can average density of earth be inferred? Answer: Based on
gravitational properties and its ettect on known masses such as orbiting satellites.
18. Density of earths crust? Answer: 2.6-3 g/cm3
QUESTIONS AND ANSWERS
usr
[COMPANY NAME] [Company address]
,1. nebular hypothesis Answer: 1. supernova and formation of primordial dust cloud
2. condensation of primordial dust forms disk shaped nebular cloud rotating counter-clockwise.
3. proto sun and planets begin to form
4. accretion of planetesimals and ditterentiation of planets and moons (4-6 billion years ago).
5. existing solar system takes shape.
2. Evidence of nebular hypotheses Answer: 1. Planets and moons revolve in a counter-
clockwise direction (not random)
2. almost all planets and moons rotate on their axis in a counter-clockwise direction.
3. planetary orbits are aligned along the suns equatorial plane (not randomly organized)
4. observations from Hubble telescope and radio astronomy indicate that other planetary systems are
forming from condensed nebular dust.
3. Terrestrial Planets Answer: Close to the sun, dense, small/rocky, silicate minerals, metallic
cores
Twelve earths would fit across the diameter of Jupiter.
4. Jovian Planets Answer: Far from the sun, low density, large, gaseous (hydrogen, methane)
5. Why does the earth and terrestrial planets have so little molecular
hydrogen comprising their respective atmosphere, yet the primordial
dust cloud was mostly comprised of hydrogen gas? Answer: Hydrogen gas and
helium gas escapes to space when put in our atmosphere.
Jupiter, saturn, and neptune maintain molecular hydrogen gas in the atmosphere because they have high
density.
6. Differentiated Earth Answer: 1. Iron Nickel Core
(outer core liquid) (inner core solid)
2. Fe-Mg silicate mantle
3. Fe-Mg-Al Silicate Crust (Ocean and Continental)
4. Oceans
5. atmosphere
7. How is the earth compositionally zoned? Answer: Along a density gradient
8. How did the earth become compositionally zoned? Answer: 1. Accretion of
planetesimals
2. initial heating due to kinetic energy of colliding planetesimals and compressional heating.
3. additional heating from radioactive decay.
,4. iron catastrophe Answer: melting temp of iron reached and dense iron nickel sink to core and lighter
materials are displaced outwards (including silicate rock of mantle and crust, ocean waters and
atmospheric gases)
, 5. earth becomes compositionally zoned based on density (densest iron nickel in core-least dense
materials comprise the atmosphere) 500 mil yrs after the initial accretion process.
6. convective overturn in asthenosphere, mantle and outer core still occur today.
9. Why did the earth heat up and then rapidly cool during the
differentiation process? Answer: When earth was solid-heat gain was greater than the heat
lost to space. This means that the internal temperature rises until it exceeded the melting temp of
oxygen and nitrogen until exceeded iron nickel catastrophe. Earth is completely molten and then
compositionally zoned.
When earth was liquid- convection-hot gas rises , after it became molten, the earth rapidly cooled ott and
solidified.
10. Why does earth possess little evidence of its early accretion
history? Answer: Because of weathering, plate tectonics, moon has no atmosphere and
biosphere.
11. Emissions from degassing of the earth during its differentiation.
Answer: h2o, co2, h2, he, n2
12. Where did molecular H and He escape to? Answer: space
13. When did oxygenation of the atmosphere occur? Answer: later following
evolution of marine algae and plants that use photosynthesis to convert co2 to o2 as a part of
their life processes.
14. What layers of the earth can be directly observed? Answer: crust and
uppermost mantle.
15. Evidence of initial composition of the solid earth based on
meteorite studies. There are two major classes of meteorites that
dominate collected samples. Carbon based meteorites are much
rarer, but indicate that the prescursor of life was present early on. Answer:
1. Metallic meteorites (iron nickel density 9.0-10 gm/cm3)
2. chondritic meteorites Answer: Fe-Mg silicate, rocky, density is 3.0-3.3)
3. carbonaceous chondrites (rare)
16. What is earths average density? Answer: 5.5 g/cm3
17. How can average density of earth be inferred? Answer: Based on
gravitational properties and its ettect on known masses such as orbiting satellites.
18. Density of earths crust? Answer: 2.6-3 g/cm3
