What are the necessary conditions for any system to be aromatic?

What are geostationary satellites? What are the necessary conditions for a satellite to appear stationary ?

What do you understand by reversible and irreversible processed? Give examples. What are the necessary conditions for a process to be reversible?

State two necessary conditions for rusting.

What are the conditions for a compound / species to be aromatic according to Huckel 's rule ?

(i) State the principle on which the working of an optical fiber is based. (ii) What are the necessary conditions for this phenomenon to occur ?

What is the necessary condition for hydrogen bonding?