Electron Configuration Orbital Notation Lewis-Electron Dot Diagram Electrons in Atoms Electron Configuration Orbital Notation Lewis-Electron Dot Diagram

Electron Configuration A form of notation which shows how the electrons are distributed among the various atomic orbital and energy levels Example of e- configuration for Hydrogen: 1s1 Total # of electrons in that sublevel. 1st column of s-block S-Block Principle Quantum number which stands for the energy level

Periodic Patterns Yellow represents the s-block Pink represents the p-block Green represents the d-block Orange represents the f-block S-block S-block d-block p-block f-block

Order of filling sublevels 1s2 2s2 2p6 3s2 3p6 4s2 You must fill in each sublevel with its maximum number of electrons before you move to the next energy level Sublevel (block) # of orbitals Maximum # of e- S 1 2 p 3 6 d 5 10 f 7 14

Examples e- configuration for Oxygen Oxygen has 8 electrons and is in period 2 1s2 2s2 2p4 6 valence electrons 2 energy level and located in the p-block

Practice Write the e- configuration for the following elements: Helium Neon Sulfur Calcium

Orbital Notation Every box represents an orbital Sublevel (block) # of orbitals Maximum # of e- S 1 2 p 3 6 d 5 10 f 7 14 Every box represents an orbital Every arrow represents electrons

General Rules Pauli Exclusion principle Hund’s rule Every orbital can only hold 2 electrons with opposite spins Hund’s rule Within a sublevel, place one e- per orbital before pairing them. Right WRONG

Example: Orbital Notation for Oxygen: Remember: 1s2 2s2 2p4 Orbital Notation for Oxygen: You know the e- configuration for oxygen is 1s22s22p4 Remember: Every orbital is represented by a box Every orbital holds a maximum of 2 electrons s-block represented by 1 orbital p-block represented by 3 orbitals

Practice Show orbital notation for the following elements: Helium Neon Sulfur Calcium

Lewis Electron Dot Structure An atom’s Lewis electron dot structure consists of : element’s symbol-which represents the atomic nucleus and inner-level electrons, surrounded by dots representing the atom’s valence electrons. Source: Glencoe Chemistry Matter and Change pg. 140

How do we use the periodic table to draw Group 1A: 1 valence electron Group 3A: 3 valence electrons Group 4A: 4 valence electrons Group 5A: 5 valence electrons Group 6A: 6 valence electrons Group 7A: 7 valence electrons Group 8A: 8 valence electrons Group 2A: 2 valence electrons How do we use the periodic table to draw Lewis electron dot structures? Identifying the representative group number will allow you to determine the number of valence electrons. Here’s how….

Writing out Lewis Electron Dot Structure Group # = number of valence electrons Example: Phosphorus is on group 5A, so it has 5 valence electrons. Step 3: Continue placing one electron on each of the four sides of the symbol & then pair up the electrons until you have placed all valence electrons around the symbol Step 1: write the element symbol P Step 2: Start at the top of the symbol and place one electron

Practice Write the Lewis Electron Dot Structure for the following elements: Helium Neon Sulfur Calcium

Questions??