Question : The elements known as primary nutrients for plants are:

Option 1: nitrogen, phosphorus and potassium

Option 2: nitrogen, oxygen and silicon

Option 3: potassium, boron and nitrogen

Option 4: nitrogen, phosphorous and iron

Question : Which one of the following forms of phosphorus is most reactive?

Option 1: Black phosphorus

Option 2: White phosphorus

Option 3: Violet phosphorus

Option 4: Red phosphorus

Question : Calcium salt used as fertilizer is

Option 1: Calcium Carbide

Option 2: Calcium Carbonate

Option 3: Calcium Cyanide

Option 4: Calcium Sulphate

Question : Which one of the following non-metals shows allotropy in the liquid state?

Option 1: Carbon

Option 2: Sulphur

Option 3: Phosphorus

Option 4: Bromine

Question : ______ gas is used for the manufacturing of bleaching powder.

Option 1: Nitrogen

Option 2: Sulphur

Option 3: Oxygen

Option 4: Chlorine