All objects exert buoyant force when in water. Water exerts a force as well. If the force exerted by the object is more than that of the water, it sinks. If it is less, water supports it from beneath and hence it floats.

 Stimuli or changes outside of the human body to which we respond  - like touching a hot rod or iron.

Food preservatives like sodium benzoate ,salicylic acid.

Bases for preventing excess acidity in the soil like quicklime(calcium oxide),slaked lime and chalk(calcium carbonate).

Insecticides for killing unwanted pests and insects like locusts that destroy large acres of farmland like DDT,aldrin and chlorinated hydrocarbons,gamaxin and flit.

Fertilisers like nitrogen compounds(urea,ammonium nitrate,ammonium sulphate),superphosphate.

Herbicides for killing weeds and fungicides.

Conversion of atmospheric nitrogen … Read more