What is meant by nuclear waste? State one way for the safe disposal of nuclear waste?

State three safety precautions that you would take while handling the radioactive substances.

What do you mean by background radiations? Name it's two sources. Is it possible for us to keep ourselves away from it?

What is nucleus of an atom? Compare it's size with that of the atom. Name it's constituents. How is the number of these constituents determined by the atomic number and mass number of an atom?