Answer:
pH reducing agent for acidic soils
Explanation:
Gypsum is not used to reduce soil pH because it will displace the soil H+ but there's no means of extracting the H from the soil. So the pH of the soil remains the same.
Od. 0-0 does not pair of the Molecules bid it’s polar bond due to certain pairs of molecules not being present within its presentations
Answer: D) helium.
Explanation:
Nuclear fission is a process which involves the conversion of a heavier nuclei into two or more small and stable nuclei along with the release of energy.

Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.
Example: 
Thus when deuterium and tritium , the two isotopes of hydrogen are fused, a heavier nuclei helium is being formed from two smaller nuclei releasing a neutron.