Acc. to Law of Conservation of Mass
Mass of reactants=Mass of Products
Let mass of Oxygen be x.
So,
50.6+x=452
x=452-50.6
=401.4 g
Explanation:
From your information above, assume 1 month is 28 days
1 days=24hours ; 28 days=672 hours (just multiply 1 days with 28)
1 hour=60minutes ; 672 hours=40,320 minutes
.. 1 month=40,320 minutes
10%
At each trophic level only small proportion of energy is transferred to the next level