What are the best belements to do a research on?? ( Atomic Number should be between 4-30)

2 answers

What kind of research do you want to do? What do you want to know about these elements?
Carbon would be an excellent choice. It is the basis of organic chemistry, and an essential ingredient of life. It also has very interesting chemical properties and allotropic forms.

What you would be doing would probably not be considered research in the scientific sense. It would be a literature search to educate yourself.