History of Earth Benchmark

Question 1

How old is our earth?

Answer 1

4.54 to 4.65 billion years old

Question 2

How does the earth change?

Answer 2

Biologically and Geographically

Question 3

How did accretion form the earth?

Answer 3

1. Fast Planetesimals collide
2. Kinetic energy because heat energy
3. Rising heat melts it all together
4. Differentiation sorts material by density making layers

Question 4

How did moon form?

Answer 4

Giant impact. Mars sized planet named Theia impacted earth. Some of pieces blasted off earth making the moon.

Question 5

What degree is earth’s axis?

Answer 5

23.5

Question 6

What does earth being tilted do?

Answer 6

Affects climate

Question 7

How did volcanos create the atmosphere and ocean?

Answer 7

1. mixture of metals, nonmentals and gasses
2. They erupt and release these
3. volcanic outgassing released 1/2 of ocean water and carbon dioxide in air.

Question 8

How did comets and meteorites create the atmosphere and ocean?

Answer 8

Hit earth and release 1/2 of all water and most gasses we need here.

Question 9

What was the most important thing brought to earth by comet?

Answer 9

Nitrogen.

Question 10

What is the greatest oxygenation event?

Answer 10

The formation of oxygen by photosynthetic cyanobacteria between 2.4 and 2.0 billion years ago.

Question 11

Oxygen bonded with iron in the ocean water causing what to form?

Answer 11

Rust.

Question 12

What happened when the iron was rusted out of the ocean?

Answer 12

Oxygen filled the atmosphere and ocean.

Question 13

What are colonies of cyanobacteria?

Answer 13

Stromatolites

Question 14

What does BIF stand for?

Answer 14

Banded Iron Formations

Question 15

What is a BIF?

Answer 15

Rocks produced from rust in ocean.

Question 16

The iron in our steel comes from what?

Answer 16

BIF

Question 17

What are mass extinctions?

Answer 17

Changes on Earth that wipe out large amounts of living things.

Question 18

What can cause most mass extinctions?

Answer 18

1. Volcanic Eruptions
2. Ocean Currents
3. Climate
4. Ice Ages

Question 19

How else can mass extinctions be caused?

Answer 19

Comets and meteorites

Question 20

What is catastrophism?

Answer 20

earth changes suddenly and violently with storms, floods, meteorites, volcanic eruptions, earthquakes

Question 21

What is uniformitarianism?

Answer 21

Earth changes suddenly with rock cycle, plate tectonics, ice age.

Question 22

What is relative age dating?

Answer 22

Figuring out which rock is more aged than another. NOT putting a specific time on it.

Question 23

Law of original horizontality?

Answer 23

all sedimentary rocks are deposited in flat sheets covering large land areas

Question 24

law of superposition?

Answer 24

Oldest rock should be at bottom, youngest at top

Question 25

Unconformities?

Answer 25

missing gaps in the rock record 1. Rock is eroded 2. Time passes 3. New rock is deposited

Question 26

angular unconformities?

Answer 26

flat layers of rock on top of tilted ones

Question 27

disconformities?

Answer 27

Clear erosion between two layers of horizonal flat rocks

Question 28

Nonconformities?

Answer 28

sedimentary rock on top of of either igneous or metamorphic rock

Question 29

What is absolute age dating?

Answer 29

1. Puts an actual age on something 2. Both organic remains (carbon dating) and igneous rocks 3. uses radioactive atoms

Question 30

What is radioactive decay?

Answer 30

1. radioactive atoms (parent atoms) don't stay radioactive 2. Lose proteins from nucleus (the decay) 3. lose a protein it's called daughter atom

Question 31

How many types of radioactive decay are there?

Answer 31

3

Question 32

What is a decay rate?

Answer 32

Time it takes one radioactive atom to decay

Question 33

Why do decay rates start out fast and slow down?

Answer 33

More atoms at the beginning

Question 34

What is half life?

Answer 34

When half of radioactive atoms have decayed

Question 35

Do half lives change?

Answer 35

No

Question 36

Does it matter how many atoms there are with half life?

Answer 36

No

Question 37

How did we put an age on the earth?

Answer 37

We compared uranium to igneous rocks on the moon, earth, and meteorites to determine half life

Question 38

How old is the earth?

Answer 38

4.54 billion years old