Developments Leading to the Bohr's Model of Atom

2.3 Developments Leading to the Bohr's Model of Atom

Rutherford's nuclear model left two loud, unanswered questions — why atoms are stable at all, and why they emit light only at particular wavelengths. Historically, two developments played a major role in the formulation of Bohr's model of the atom:

1. The dual character of electromagnetic radiation — radiation possesses both wave-like and particle-like properties.
2. Experimental results regarding atomic spectra — atoms emit and absorb light only at specific, discrete wavelengths, producing line spectra rather than continuous rainbows.

The first development is built up over the next two subsections: the wave nature of electromagnetic radiation (2.3.1) and its particle nature in Planck's quantum theory and the photoelectric effect (2.3.2). The second — atomic spectra as the evidence for quantised energy levels — follows in 2.3.3. …