Question

multiple choice question
what question did bohrs quantum model of the atom seem able to answer, for the first time?
why is energy quantized?
where are the positive and negative charges in an atom located?
what is the charge on an electron?
why are atomic emission spectra discontinuous?

Explanation:

Bohr's quantum model of the atom proposed that electrons orbit the nucleus in discrete energy levels. When an electron transitions from a higher energy level to a lower one, it emits a photon with a specific energy corresponding to the difference in energy levels. This explains why atomic emission spectra are discontinuous (consisting of discrete lines), as each line corresponds to a specific energy transition.

• The question of why energy is quantized was a more fundamental concept in quantum theory that wasn't uniquely "answered first" by Bohr's model in the same context as the emission spectra.
• The location of positive and negative charges in an atom was already addressed to some extent by previous models like Rutherford's nuclear model (positive charge in the nucleus, negative - charged electrons outside).
• The charge on an electron was determined through experiments like Millikan's oil - drop experiment, not by Bohr's atomic model.

Answer:

Why are atomic emission spectra discontinuous?