Questions

Generally, plants absorb dissolved nitrates from soil and convert them into free nitrogen.

• Free nitrogen is simply molecular nitrogen (N2).

• Nitrogen, in its molecular form, consists of two nitrogen atoms bound together with a triple bond.

Spleen is called as the graveyard of RBC Red Blood Cells where they are selectively destroyed/recycled by macrophages.

The defining right of a representative democracy is the ability to vote for representatives to make decisions on their behalf.

In democratic government, elections are held regularly, in which voters vote for someone who will serve in the levels of local, state, and federal government.

Pitot tube is used to measure stagnation pressure.

Para-amino salicylic acid (PAS) is used in the treatment of Tuberculosis.

Processes that require or give off heat will be limited to changes of state, known as phase changes, and changes in chemical constitution, or chemical reactions. Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.

An exothermic process is one that gives off heat, which is transferred to the surroundings. An endothermic process is a reaction which heat has to be supplied to the system from the surroundings.

Here in all the given options, heat is taken away from them to change there phase. 

Liquid to Solid --- Freezing

Gas to Liquid --- Condensation

Gas to Solid --- Deposition 

are all examples of exothermic processes.