What are e.m. waves?How are they produced?

What are positive and negative charges? How are these produced?

What is the frequency range of radio waves? How are radio waves produced?

What are the pollutants attacking Taj Mahal ? How are they being produced in the atmosphere ?

Name the e.m.waves,which are produced during radioactive decay of a nucleus. Write their frequency range.

An explosion takes place at the bottom of a lake.What type of waves are produced inside the water?

When e.m. waves strike a surface, they exert..........on it.