Questions

The International Waste Picker's Day is observed on 1st March in memory of the massacre in Colombia in which 11 workers were brutally killed University of Barranquilla.

The American noncommissioned officer tradition began with creation of the Continental Army in 1775 at the beginning of the American Revolution. They adopted NCO traditions from French NCO.

Nitrogen is found as a diatomic molecule (N2) in nature. There is a triple bond between the two nitrogen atoms.

The triple bond is pretty strong. Therefore, it needs a lot of energy to break those bonds and participate in a reaction. So nitrogen is commonly referred to as and used as an inert gas (high abundance & low cost.) However, it’s not truly inert like most noble gases. Nitrogen does react if the conditions are met. But those conditions are not exactly mild, but are not as extreme as for noble gases.

It forms nitric oxide and nitrogen dioxide with oxygen, ammonia with hydrogen, and nitrogen sulfide with sulfur.

It is ABACUS.

Words formed are as below 

BUS
CAB
CUB
US

Life originated by chemosynthesis was proved in the laboratory by Miller.