Top Posters
Since Sunday
t
7
m
6
k
6
F
5
j
5
t
5
j
5
G
5
f
5
a
5
d
5
c
5
Home Q & A Board Science-Related Homework Help Physics
New Topic  
symbo symbo
wrote...
Go to Answer
Posts: 1970
Rep: 2 0
7 years ago
The large amount of free oxygen in the Earth's present atmosphere is primarily a result of
A)   out-gassing by volcanoes and other geological processes.
B)   biological processes such as photosynthesis.
C)   splitting of carbon dioxide into carbon and oxygen by solar ultraviolet light.
D)   carbon dioxide becoming dissolved in the oceans, releasing oxygen.
Textbook 
Discovering the Universe

Discovering the Universe


Edition: 7th
Authors:
Read 170 times
1 Reply
Replies
Answer verified by a subject expert
hyponoticahyponotica
wrote...
#1
Top Poster
Posts: 1396
Rep: 28 0
7 years ago
Sign in or Sign up in seconds to unlock everything for free
More solutions for this book are available here
1

Related Topics

symbo Author
wrote...

7 years ago
Smart ... Thanks!
big_larry_samp
wrote...

Yesterday
You make an excellent tutor!
courtneyrmcd
wrote...

2 hours ago
Helped a lot
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1016 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 169
  
 184
  
 151
Your Opinion
Who will win the 2024 president election?
Votes: 7
Closes: November 4
Previous poll results: Which country would you like to visit for its food?