Answer:
Bohr's model of the atom
Explanation:
This model of the atom was proposed by Niels Bohr in 1915.
In this model, the atom has a nucleus containing protons (positively charged) of very small size; the electrons (negatively charged) orbit around the nucleus.
However, unlikely Rutherford's model of the atom, in Bohr's model the electrons cannot have any energy/orbit. In fact, their energies are quantized: this means that the electrons can only be located at specific orbits that corresponds to specific energy levels, and they cannot be found between two orbits.
This model allows to explain the discrete spectra observed in the absorption/emission of light from gases. In fact:
- When an electron jumps from a higher energy level to a lower energy level, it releases a photon whose energy is exactly equal to the difference in energy between the two levels
- When an electron jumps from a lower energy level to a higher energy level, it absorbs a photon whose energy is exactly equal to the difference in energy between the two levels
So, the light absorbed/emitted by a gas can only have some specific (discrete) wavelengths, that correspond to the energy absorbed/emitted by the electrons in the orbit.
