Question

Why won't a chain reaction occur in natural uranium?

a.) There is too much U-235 in nature to reach a critical mass.
b.) Uranium is not found in nature. We create it in laboratories.
c.) Uranium is too rare in nature.
d.) Most natural uranium is U-238, which will not go through fission easily.

Answer 1

U-235 is needed for fission nearly pure and is rarer than U-238. Draw the right conclusion.

Answer 2

this is like a riddle.

Answer 3

http://en.wikipedia.org/wiki/Uranium-235

first paragraph

Answer 4

and maybe the first paragraph here

http://en.wikipedia.org/wiki/Uranium-238

Answer 5

There is too much U-235 in nature to reach a critical mass. - this makes no sense. how can there be TOO much for critical mass.

Uranium is not found in nature. We create it in laboratories. - is this one a reasonable choice?

Answer 6

sure.

Answer 7

?

Answer 8

...Does uranium occur in nature, or not?

Answer 9

b.) Uranium is not found in nature. We create it in laboratories.
c.) Uranium is too rare in nature.
d.) Most natural uranium is U-238, which will not go through fission easily.

If you read the first two paragraphs of the links above, this should not be a tough decision.