« previous next »

Author Question: How did oxygen (O2 ) get into Earth's atmosphere? A) It was captured from the solar nebula. B) ... (Read 75 times)

rachel9

  • Sr. Member
  • ****
  • Posts: 495
on: Jul 27, 2018
How did oxygen (O2 ) get into Earth's atmosphere?
 
  A) It was captured from the solar nebula.
  B) It was outgassed from volcanoes.
  C) It came from chemical reactions with surface rocks.
  D) It was released by life through the process of photosynthesis.

Question 2

An intermediately wound barred spiral galaxy would be
 
  A) BS2.
  B) BSE.5.
  C) SBb.
  D) S2B.
  E) SIrr.


amanda_14

  • Sr. Member
  • ****
  • Posts: 342
Reply #1 on: Jul 27, 2018
Answer to Question 1

D

Answer to Question 2

C


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

rachel9

  • Sr. Member
  • ****
  • Posts: 495
Reply #2 on: Jul 27, 2018
TY


amanda_14

  • Sr. Member
  • ****
  • Posts: 342
Reply #3 on: Jul 27, 2018
You're welcome


« previous next »
 

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

Did you know?

When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.

Did you know?

The highest suicide rate in the United States is among people ages 65 years and older. Almost 15% of people in this age group commit suicide every year.

Did you know?

Approximately 70% of expectant mothers report experiencing some symptoms of morning sickness during the first trimester of pregnancy.

Did you know?

More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.

The Formation of the Solar System The Formation of the Solar System
Origin of a Solar Flare Origin of a Solar Flare
Earth’s Revolution and Rotation: The Causes of Earth’s Seasons Earth’s Revolution and Rotation: The Causes of Earth’s Seasons
Earth’s Biomes "الأرض الحيوية" Earth’s Biomes "الأرض الحيوية"
Orbital Motion of Earth and Other Planets Orbital Motion of Earth and Other Planets
Partial pressures (in mm Hg) for oxygen (red boxes) and carbon dioxide (blue boxes) in the atmospher Partial pressures (in mm Hg) for oxygen (red boxes) and carbon dioxide (blue boxes) in the atmospher
Video: Frequency of stimulation and force (Recruitment of motor units and force)

For a complete list of videos, visit our video library