Subham Roni

ohk understood! thanks everyone ! A few decades ago, electrons were in fixed circular path. Now its a cloud and a particle with dual nature! No one can exactly say how the universe work!

OKie.. Got it.. I wanted the 2nd answer! This forum is awesome! Bookmarked it!

Bohr derived his formula using one the centrifugal and centripetal forces of electron and nucleus. But why can't we consider the electron in 2nd orbit?

Ok I am being specific why I asked the question. Electrons have negative energy values. At infinite distance(out of boundary of atom) the electron is considered to have no energy at all as it isn't attracted by the protons. I understood this. But as it moves closer to the nucleus, it is attracted by the protons and energy is released and energy of system decreases. Why?

Why Bohr's theory cannot explain the atomic spectra of He,Li, etc, i.e., systems with more than one electrons?

Why does the energy of a system decrease when two charged particles attract each other?