An atom’s emission of light with a specific amount of energy confirms that atoms must have a dense central mass surrounded by electrons at a distance.
electrons emit and absorb energy based on their position around the nucleus.
electrons can only be found within predicted areas surrounding the nucleus.
atoms are made of positive and negative charges.

The correct answer is B. Electrons emit and absorb energy based on their position around the nucleus.

Explanation:

In general, an atom's emission of photons (light) is the result of electrons, which are the negative charge particles that orbit the nucleus. Moreover, the emission of light is likely to occur if the electron is located at a specific energy level (position in the atom) and it moves to a lower level as this requires the loss of energy in the form of photons. Also, the electron can absorb the photons and as a result gain enough energy to move to a higher level. This implies the atom's emissions of light shows the relationship between electrons emitting and absorbing energy and their position or energy level.

wavelength variability is the right one

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.