Which of the following does not cycle into the atmosphere?
a. the carbon cycle
b. the phosphorus cycle
c. the nitrogen cycle
d. the oxygen cycle

b. the phosphorus cycle

Explanation:

The phosphorus cycle is one of the important biogeochemical cycle. The phosphorus in it's various forms moves in various spheres of earth including lithosphere, hydrosphere and biosphere. But it is not the part of atmosphere. It is an important element present in all forms of life. It is important ingredient of nucleic acids like DNA and RNA which are genetic materials present in living organisms. It is also the part of energy currency molecules like ATP (Adenosine triphosphate).

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg