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Quantum Theory. Every electron on an atom is in a definite state (energy level) with a definite energy. In order for an electron to change energy levels, a photon must be either absorbed or emitted, governed by Δ E = hc/ λ
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Quantum Theory Every electron on an atom is in a definite state (energy level) with a definite energy. In order for an electron to change energy levels, a photon must be either absorbed or emitted, governed by ΔE = hc/λ The allowed energy levels for an electron on an atom are governed by four quantum numbers, n, l, m and s.
Rules for determining the ground state of an atom. • The Pauli exclusion principle. No two electrons on an atom can have the same four quantum #’s • The Aufbau principle. When electrons go on an atom, they fill the lowest available energy level. • Hund’s rule. When electrons fill a sit of degenerate (ie. same energy) orbitals, they do so in a way which maximizes the spin.