Denitrification is a process where nitrate (NO3−) is reduced to nitrogen gas (N2) or other gaseous forms. The key microbes involved include:
Nitrosomonas (D): It is involved in nitrification, not denitrification. Rhizobium (A) and Azotobacter (E): These are nitrogen-fixing bacteria, not involved in denitrification.
Europium (Eu) resembles Calcium (Ca) in the following ways:
(A). Both are diamagnetic
(B). Insolubility of their sulphates and carbonates in water
(C). Solubility of these metals in liquid NH3
(D). Insolubility of their dichlorides in strong HCI
Choose the correct answer from the options given below: