Concept: The transition from classical deterministic orbits to quantum probabilistic electron clouds was a monumental shift in atomic theory.
Formula: $$ \hat{H}\psi = E\psi $$
Solution: - Bohr proposed fixed, circular, deterministic orbits (which violated the uncertainty principle).
- Erwin Schrödinger formulated the wave equation, where the square of the wave function (\(|\psi|^2\)) yields the mathematical probability density of finding an electron in a specific region of space (the orbital).
- This established the quantum mechanical model of the atom based entirely on probabilities rather than fixed paths.
Why other options are incorrect: Bohr's model is non-probabilistic. de-Broglie introduced wave-particle duality but not the probabilistic wave function. Hund established orbital filling rules.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.