ELECTRONIC-CONFIG.QUANTUM-NUMBERS_students
Course Overview
Topic: Electron Configuration & Quantum Numbers
Instructor: Teacher Mitz
Objectives
Write the electron configuration of elements.
Describe the Aufbau principle.
Determine different quantum numbers.
Review of Quantum Mechanics
Activity 1.2: Scientist Contributions
Niels Bohr - B: Electrons found in definite orbits around the nucleus.
Louis de Broglie - D: Electrons are both particles and waves.
Erwin Schrödinger - A: Mathematical wave equation for hydrogen atom.
Karl Werner Heisenberg - C: Uncertainty principle regarding position and momentum of electrons.
Quantum Mechanical Model
Derives from Schrödinger's equation solution.
Probability of finding an electron is highest in darker areas as shown in figures.
Describes electrons in shells (principal energy levels), which include sublevels: s, p, d, f, g.
Principal Quantum Numbers
Principal quantum number (n) indicates the energy level.
Max electrons in a level: 2n².
Orbitals
Specific energy values and shapes:
s orbitals: Spherical
p orbitals: Dumbbell-shaped (px, py, pz)
Electron Configuration
Distribution arrangement of electrons in orbitals.
Electrons fill from lower to higher energy levels.
Principles Governing Electron Configuration
Aufbau Principle
Electrons fill available orbitals from low to high energy.
All electrons in ground state occupy the lowest energy levels.
Hund’s Rule
Electrons occupy orbitals singly before pairing up.
Applies to subshells: 1s, 2s, 2p, etc.
Pauli Exclusion Principle
Electrons in the same orbital must have opposite spins.
No two electrons can share identical quantum numbers.
Magnetism in Atoms
Paramagnetism
Atoms with unpaired electrons are attracted to magnets.
Diamagnetism
Atoms with all paired electrons are repelled by magnets.
Quantum Numbers
Principal Quantum Number (n)
Refers to the energy level (n = 1-7).
Azimuthal Quantum Number (l)
Defines sublevel shape:
0 = s, 1 = p, 2 = d, 3 = f.
Magnetic Quantum Number (m_l)
Describes orientation of orbitals in space.
Spin Quantum Number (m_s)
Indicates electron spin: +1/2 or -1/2.
Examples and Practice
Identify quantum numbers for:
Aluminum
Rubidium
Xenon