Grab Bag
This term describes the process where earth formed through repeated collisions with meteors, asteroids, and comets, gradually getting bigger and bigger
Accretion
Earth's early atmosphere gases were similar to what comes out of these
volcanoes
when a dense basalt crust and a less dense granite crust are being pushed together, what is the result?
the more dense basalt crust subducts under the less dense granite crust
The mantel has this type of heat transfer, which is what drives the movement of tectonic plates
Convection
In a radioactive substance, what happens to the amount of parent material over time?
It decreases
The building blocks of life
Amino Acids
Early earth was hotter than today because.... (more than 1 correct answer!)
-more radioactive isotopes
-more impacts = more heat
What gas is 21% of our atmosphere today?
Oxygen
It Doesn't!
The 2 sources of water that filled our oceans
Volcanoes and "space" (comets, meteorites, asteroids)
This gas was lost in our atmosphere due to it's low mass
hydrogen
This rock forms through weathering, erosion, and layers cementing together
Sedimentary
The reason the earth is in layers
Density
The term to describe when one tectonic plate is pushed under another
subduction
The first life FOSSILS
Stromatolites
This stage of the water cycle went on for millions of years at one point
precipitation
In a radioactive substance, what happens to the amount of daughter product as time passes?
It increases
TWO ways in which bacteria are significant in the history of the earth:
They are the first form of life
They produce the first oxygen gas
Which layer of the earth is the most dense?
The core
When 2 tectonic plates are being pulled apart, what would be the result?
New crust forms
If a 30g sample of Oxygen 18 has a half-life of 20 years, what is the half life of a 60g sample?
20 years
If water on earth first existed as water vapor, what had to happen for it to become liquid
Earth had to cool
A mid ocean ridge is a place where plates are pulled apart and new crust forms. By this logic, the farther you get from the ridge, the ______ the rock gets
older
Red bands in rocks tell us this was present when that rock layer formed:
oxygen
Look at this square from the periodic table. How many NEUTRONS does this element have?
5