Question

What are (a) normal elements, (b) harmful elements? Give two examples of each

Answer 1

Answer:

Normal elements are elements which do not emit any harmful radiation and have a normal reaction

For eg Oxygen and Helium

Harmul elements are elements which emit harmful radiation and do not have a normal reaction

For eg Uranium and Radium

Answer 2

Answer:

The elements that do not give out any harmful radiations are called Normal Elements. Example: Fluorine (F), Chlorine (Cl), Bromine (Br), etc.

Whereas, the elements that give out harmful radiations are called Radioactive Elements. Example: Uranium (U), Thorium (Th), Potassium (K), etc.

Hope it Helps