This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: How long did it take for oxygen to build up in the Earth's atmosphere to its present levels? A) ... (Read 68 times)

809779

  • Hero Member
  • *****
  • Posts: 579
on: Jul 27, 2018
How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?
 
  A) at least 542 million years
  B) at least 360 million years
  C) at least 2 billion years
  D) at least 3.5 billion years

Question 2

Express the following number to three significant figures: 21.25 m
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

blakeserpa

  • Sr. Member
  • ****
  • Posts: 338
Reply #1 on: Jul 27, 2018
Answer to Question 1

C

Answer to Question 2

21.3 m


809779

  • Member
  • Posts: 579
Reply 2 on: Jul 27, 2018
Gracias!

Laurenleakan

  • Member
  • Posts: 309
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

« previous next »
 

Did you know?

Between 1999 and 2012, American adults with high total cholesterol decreased from 18.3% to 12.9%

Did you know?

Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.

Did you know?

Approximately 500,000 babies are born each year in the United States to teenage mothers.

Did you know?

Cyanide works by making the human body unable to use oxygen.

Did you know?

According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.

Diamond and Oxygen Diamond and Oxygen
Substance Abuse : Biological, Psychological and Sociocultural Levels Substance Abuse : Biological, Psychological and Sociocultural Levels
Cyanosis as shown here at the patient’s fingertips results from a lack of oxygen in the tissues Cyanosis as shown here at the patient’s fingertips results from a lack of oxygen in the tissues
Weather maps: Pictures of the atmosphere Weather maps: Pictures of the atmosphere
Moving currents are affected by Earth’s rotation Moving currents are affected by Earth’s rotation
Nursing Care Plan Process: Client with High Blood Lipid Levels Nursing Care Plan Process: Client with High Blood Lipid Levels
Video: Interview with Person who has Panic Attacks

For a complete list of videos, visit our video library