Ch. 5 Electron Configurations

Orbitals: 3D representation of electrons pathways

1s2 Energy Levels Represented by numbers, from 1-7. 1 = lowest energy 7 = highest energy When writing electron configurations, the order is Energy level, orbital shape, # of electrons Energy Level 1s2 Number of Electrons Orbital Shape

Diagonal Rule: Follow the Arrows

Counting Electrons in each Orbital Next to each letter (s, p, d, or f) we write the number of electrons as a superscript. Orbital Max # of Electrons s 2 p 6 d 10 f 14 Which element is represented by these electron configurations? 1s1 H 1s2 He 1s22s1 Li 1s22s22p2 C 1s22s22p63s2 Mg

Check for Understanding Write the electron configurations for the following elements: Element Electron Configuration Total # of Electrons He 1s2 2 C 1s22s22p2 6 Ne 1s22s22p6 10 Ca 1s22s22p63s23p64s2 20 Ag 1s22s22p63s23p64s23d104p65s24d9 47

Abbreviated configurations Step 1: Use elements on very right of periodic table. Step 2: Write rest of configuration Example: Ca: [Ar] 4s2 Ne: [He] 2s22p6 Cu: [Ar] 4s23d9 Zr: [Kr] 5s24d2