Save
Busy. Please wait.
Log in with Clever
or
show password
Forgot Password?
Don't have an account?  Sign up 
Sign up using Clever
or
Username is available taken
show password

Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Question

Name two gases common in Earth's atmosphere during the Precambrian time?
click to flip
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't know

Question

Scientists used index fossils and rock layers worldwide to determine the:
Remaining cards (14)
Know
0:00
edit
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Unit 4A Lesson 5

Unit 4A Lesson 5 Quiz

QuestionAnswer
Name two gases common in Earth's atmosphere during the Precambrian time? Hydrogen and Helium
Scientists used index fossils and rock layers worldwide to determine the: Geologic Time Scale
What is a body fossil? A rare fossil in which the entire organism gets preserved.
What is an Index Fossil? Fossils of organisms that were common worldwide but only lived for a defined period of time in the geologic time scale
On a graph of strontium 90, after two half lives how much radioactive material would remain in a sample? 1/4 or 25%
When did Earth's atmosphere, oceans, and continents began to develop? During the first several hundred million years of Precambrian time
How are fossils most commonly formed? When a living thing dies and is quickly covered in sediment
What is a petrified fossil? Fossils formed when minerals replace all or parts of an organisms body.
What is a mold fossil? A hollow shape formed when sediment hardens around an organism which later decays
What is a cast fossil? A solid shape of an organism formed when sediment hardens inside of a hollow mold.
Name 6 types of Fossils that we studied in Unit 4. Mold, Cast, Index, Petrified, Body , Trace
Carbon 14 and Strontium 90 are two examples of Radioactive elements that scientists use to determine: The absolute age of a rock or fossil.
What is the absolute age of a rock or fossil It's actual age in years. (a number- usually in 'mya')
What is the relative age of a rock or fossil? Its age compared to other rock layers (older/younger)
On a graph of Radioactive decay, at point 0 years, how much radioactive material would remain in a sample? 100% At pt 0, Radioactive decay has JUST begun. Either a living organism has just died OR an igneous rock has just formed.
Created by: scanto
Popular Earth Science sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards