Conservation of energy -Energy cannot be created or destroyed- The difference between each energy level is called a Quantum When energy is added to an electron, the electron will become “excited” moving to a higher energy level When the electron comes back down to its ground state energy is released----in the form of light.
Electron Configuration -Each electron is a given set of 4 quantum numbers Principle Quantum Number or Energy Level - represent by the letter “n” n= 1 <2 <3 < 4 - generally, the larger the value of “n” , the further away the electron is from the nucleus. n=1 can hold a max of 2 e- n=2 can hold a max of 8 e- n=3 can hold a max of 18 e- n= 4 can hold a max of n = 5 can hold a max of
2nd is L 4 main orbitals—(each orbital can hold 2 electrons) Provides a code for the shapes of orbital - represented by the letter “l” 4 main orbitals—(each orbital can hold 2 electrons) s-orbital –can hold 2 electrons -lowest in energy level -spherical in shape p-orbital-(can hold six electrons) -3 different p-orbitals (Px, Py, Pz) - shaped like a dumbbell
3. Magnetic quantum number (ml) - spatial orientation of the orbital that the electron occupies. Is it in Px, Py, Pz etc. 4. Spin quantum number (ms) -indicates the way the electron is spinning - ±1/2 http://winter.group.shef.ac.uk/orbitron/AOs/1s/index.html
Writing Electron configurations Copy the following on your periodic table Or you can use the Aufbau diagram(below)
Rules of electron configurations Pauli Exclusion Principle – No 2 e- can have the same set of four quantum numbers. The Aufbau Principle - Electrons fill in lowest energy levels first 1s2 2s2 2p6 3s2 3p6 Hund’s Rule (Bus Back seat Rule) - electron will fill up empty orbitals before pairing up.
At Higher levels there will be an overlap of energy levels- Writing electron configurations Ex: F= 1s2 2s2 2p5 Ar= 1s2 2s2 2p6 3s2 3p6 K= 1s2 2s 22p6 3s2 3p6 4s1 or [ Ar] 4s1 Try these: Cl: Na: Orbital Diagrams ---same concept Oxygen 8e- 1s2 2s2 2p4 http://misterguch.brinkster.net/PRA014.pdf