Answer:
F. Universe
Explanation:
Universe and Galaxies are two different things.
The correct answer is (3)
I-131 and P-32
The explanation:
according to attached table:
- we can see that the half life of p 32 is 14.28d (more than one hour)
- and the half life of I-131 is 8.021 d
(more than one hour)
and They both have β- decay mode and with half-lives greater than hour.
Pure air is a mixture of several gases that are invisible and odorless. Consists of 78% nitrogen, 21% oxygen, and less than 1% of argon, carbon dioxide.