The first one.
Hope this helps
Brainliest plz
Nails form from molten iron is considered a Physical change. Why? The molten iron is just heated in order to form a different shape which is the nail but its chemical composition is still the same. The chemical composition of the nail is still the same with iron.
Red I believe is the answer
Explanation:
Denitrification is basically a biochemical phenomenon where nitrate is used by the bacteria living in the soil for the process of their respiration instead of using Oxygen from the air, consequently, the nitrates are converted into nitrous oxide and nitrogen gas. The process of denitrification is accelerated mostly in the wet and warm soil where there is lot of nitrate available.
This process is exhibited by Alkaligenes, Pseudomonas and Bacillus etc. Most of the bacteria involved in this process are facultative aerobially heterophs who has the ability of switching to denitrification from normal respiration when they find that the normal oxygen is running out.
