Who proposed a model with electrons moving in specific layers? a) Dalton b) Thomson c) Rutherford d) Bohr

D) Bohr

Explanation:

Neil Bohr proposed The Atomic model in which he stated that electrons move around the nucleus of the atom in specific layers called 'shells.

In 1913, Bohr expanded Rutherford's idea and presented his atomic model in which he stated that the electrons moves in fixed, circular orbits around the nucleus of an atom, these called electron shells. Each shell is at a set distance from the nucleus and that distance is same for all atoms. He also stated that as the number of shells increases the distance between the shells become larger, and that electrons furthest from the nucleus have higher energy. He described these orbits/shells as energy levels. The energy of electrons in the same shell is same. This also explained the emission spectrum and how electrons lose or gain energy.