Natural radioactivity is found in heavy elements only. Explain.

What is radioactivity? What is the difference between natural and induced radioactivities?

Is it safe for the electrician to carry out electrical repairs outdoors during heavy downpour ? Explain.

Is it safe for electrician to carry out electrical repairs outdoor during heavy downpour? Explain.

Is it safe for an electrician to carry out electrical repair outdoor during heavy downpour? Explain.

The half - life period of radioactive element A is the same as the mean life time of another radioactive element B. Initially both of them have same number of atoms. The radioactive element B decays faster than A. Explain, why.

What is radioactivity ? Explain laws of radioactivity.