Electron Configuration Mapping the electrons
Electron Configuration The way electrons are arranged around the nucleus.
Quantum Mechanical Model 1920’s Werner Heisenberg (Uncertainty Principle) Erwin Schrodinger (mathematical equations using probability, quantum numbers)
Heisenberg uncertainty principle It is impossible to determine simultaneously both the position and velocity of an electron or any other particle with any great degree of accuracy or certainty.
Erwin Schrodinger Formulated equation that describes behavior and energies of subatomic particles. Leads to Quantum Mechanics: we cannot pinpoint an electron in an atom but we can define the region where electrons can be in a particular time……… called a Probability map….a 3-dimensional area in space called an ORBITAL
Principal Quantum Number, n Indicates main energy levels n = 1, 2, 3, 4… Each main energy level has sub-levels
Energy Sublevels s p d f
The principle quantum number, n, determines the number of sublevels within the principle energy level.
Orbital The space where there is a high probability that it is occupied by a pair of electrons. Orbitals are solutions of Schrodinger’s equations.
Orbitals
Orbitals in Sublevels Sublevel # Orbitals # electrons s 1 2 p 3 6 d 5 10 f 7 14
Three rules are used to build the electron configuration: Aufbau principle Pauli Exclusion Principle Hund’s Rule
Aufbau Principle Electrons occupy orbitals of lower energy first.
Orbital Diagram
Filling Order diagram
-Pauli Exclusion Principle (Wolfgang Pauli, Austria, 1900-1958) -Electron Spin Quantum Number An orbital can hold only two electrons and they must have opposite spin.
Hund’s Rule In a set of orbitals, the electrons will fill the orbitals in a way that would give the maximum number of parallel spins (maximum number of unpaired electrons). Analogy: Students could fill each seat of a school bus, one person at a time, before doubling up.
Orbital Diagram for Hydrogen
Orbital Diagram for Helium
Orbital Diagram for Lithium
Orbital Diagram for Beryllium
Orbital Diagram for Boron
Orbital Diagram for Carbon
Orbital Diagram for Nitrogen
Orbital Diagram for Fluorine
Standard Notation of Fluorine Number of electrons in the sub level 2,2,5 1s2 2s2 2p5 Main Energy Level Numbers 1, 2, 2 Sublevels
Sources https://d358g57815banh.cloudfront.net/WG4926LR9wp_nA4Ly3mr4pD2GD4Jx.ppt www.emsb.qc.ca/laurenhill/science/configuration.pdf