Moon & Early Earth Formation
Protoplanet that collided with Earth 4.5 bya
Theia
An element has 5 neutrons, 5 protons and 6 electrons.
What is this element's isotope name?
Boron-10
List the major layers of the Earth from most dense to least dense.
inner core, outer core, mantle, crust
Height of a wave
amplitude
3 pieces of evidence to prove continental drift theory
1) continents fit togther like puzzle
2) geological formations line up at coastlines of adjacent continents
3) fossil evidence ""
What caused the Earth to tilt on its axis?
Impact from Theia
Time for a radioactive isotope to decay to 50% of its original amount.
List the mantle's physical layers by increasing depth
lithosphere, asthenosphere, mesosphere
How do you measure the wavelength of a wave?
crest to crest or trough to trough
What earth layer makes of the plates?
lithosphere
Why is the moon's surface irregular looking?
Impact of asteroids, comets
Carbon-14 is a radioactive isotope with a half life of 5,730 years.
How old would carbon-14 be when there is 75% carbon-14 in the rock?
5,730 years / 2= 2,865 years
Two elements the mantle is rich with
iron and magnesium
A wave has a frequency of 20 Hz and a velocity of 500 m/s. What is its wavelength?
500 m/s / 20 Hz = 25 m
What happens to oceanic crust at a ocean-continental convergent boundary? Why?
Subduction; more dense
Earth contains 45.2% oxygen and the moon contains 44.7% oxygen. How does this prove the Giant Impact Theory?
Pieces of Theia and Earth broke up and combined after impact/orbit to accrete into the moon
The half-life of an isotope is 4 days. If at the start there are 1024 atoms of this isotope, how many atoms will there be after 12 days?
4 days/12 days= 3 half lives
(1024 atoms)(.5)(.5)(.5)= 128 atoms
Why is the inner core solid?
Pressure has more of an effect than temperature
What happens to the velocity of P & S waves as they travel from the crust to the mantle? Why?
Velocity drops at each new layer due to change in density
Geological formation at a continental crust divergent boundary
rift valley
Why was the early Earth so hot? Give 3 reasons.
Collisions, radioactivity, compression
If radioactive Plutonium goes through alpha decay, what new element does it become?
Uranium (looses 2 neutrons and 2 protons)
Compare oceanic and continental crust by: age, thickness, and composition
Oceanic- newer, thinner (7km), basalt
Continental- older, thicker (40km avg), granite
Give FOUR differences between S and P waves.
P- primary, faster, longitudinal, side-to-side, through all materials
S- secondary, slower, transverse, up & down, not through liquid
Two pieces of evidence to prove plate movement at a mid-ocean ridge
1) age of rocks (using radioactive dating)
2) patterns in rocks on adjacent sides of ridge