Which process is spontaneous?
a. electrolysis of water into oxygen and hydrogen
b. spreading of a strong fragrance of perfume in a room
c. separation of sodium and chlorine from sodium chloride
d. removal of iron filings from a mixture by using a magnet

The process spreading of a strong fragrance of perfume in a room, is spontaneous.

Explanation:

A spontaneous process is defined as the process which takes place on its own without any external force.

Electrolysis of water into oxygen and hydrogen requires an electric current to passed through the water. This means external force, that is, electric current must be passed for electrolysis.

Spreading of a strong fragrance of perfume in a room is a spontaneous as it does not require any external force by the molecules to spread across the room.

Separation of sodium and chlorine from sodium chloride will require an external force for the separation of atoms of sodium chloride.

Removal of iron filings from a mixture by using a magnet, here magnet is providing external force to remove iron filings from the mixture. Hence, this process in not spontaneous in nature.

Thus, we can conclude that the process spreading of a strong fragrance of perfume in a room, is spontaneous.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.