« previous next »

Author Question: How did oxygen (O2 ) get into Earth's atmosphere? A) It was captured from the solar nebula. B) ... (Read 80 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?

The calories found in one piece of cherry cheesecake could light a 60-watt light bulb for 1.5 hours.

Did you know?

Disorders that may affect pharmacodynamics include genetic mutations, malnutrition, thyrotoxicosis, myasthenia gravis, Parkinson's disease, and certain forms of insulin-resistant diabetes mellitus.

Did you know?

A recent study has found that following a diet rich in berries may slow down the aging process of the brain. This diet apparently helps to keep dopamine levels much higher than are seen in normal individuals who do not eat berries as a regular part of their diet as they enter their later years.

Did you know?

In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.

Did you know?

Although not all of the following muscle groups are commonly used, intramuscular injections may be given into the abdominals, biceps, calves, deltoids, gluteals, laterals, pectorals, quadriceps, trapezoids, and triceps.

Mechanisms of water movement from soil through plants to the atmosphere. Mechanisms of water movement from soil through plants to the atmosphere.
Astronomers identified 12-billion-year-old white dwarf stars only 100 light years away from Earth Astronomers identified 12-billion-year-old white dwarf stars only 100 light years away from Earth
Photoaging solar elastosis; senile keratosis Photoaging solar elastosis; senile keratosis
Earth’s history spans 4.5 billion years. Geologists and paleontologists have pieced together the his Earth’s history spans 4.5 billion years. Geologists and paleontologists have pieced together the his
Earth’s Spheres Earth’s Spheres
Earth-Sun Relationships Earth-Sun Relationships
Video: Interpreting a cladogram Animation

For a complete list of videos, visit our video library