140 likes | 315 Views
Atomic Structure II. Electron Configurations. Atomic Orbitals. Each electron is assigned to: Primary energy level (shell), n Orbital type in the shell (s,p,d,f) Specific orbital of the type
E N D
Atomic Structure II Electron Configurations Barbara A. Gage PGCC CHM 1010
Atomic Orbitals • Each electron is assigned to: Primary energy level (shell), n Orbital type in the shell (s,p,d,f) Specific orbital of the type Because of repulsion considerations only 2 electrons can occupy any orbital (spinning in opposite directions) Barbara A. Gage PGCC CHM 1010
Atomic Shells and Orbitals Barbara A. Gage PGCC CHM 1010
This diagram shows the energy levels of the atomic orbitals. Electrons fill orbitals from bottom to top of the diagram. Barbara A. Gage PGCC CHM 1010
A vertical orbital diagram for the Li ground state. no color-empty light - half-filled The electron configuration is written as: 1s22s1 # electrons in orbital orbital dark - filled, spin-paired shell Barbara A. Gage PGCC CHM 1010
You can use a chart like this to determine the electron configuration. (But there is an easier way.) Barbara A. Gage PGCC CHM 1010
A periodic table of partial ground-state electron configurations. Barbara A. Gage PGCC CHM 1010
PROBLEM: Using the periodic table on the inside cover of the text (not Figure 8.12 or Table 8.4), give the full and condensed electrons configurations, partial orbital diagrams showing valence electrons, and number of inner electrons for the following elements: full configuration condensed configuration partial orbital diagram 4s1 3d 4p Determining Electron Configuration (a) potassium (K: Z = 19) (b) molybdenum (Mo: Z = 42) (c) lead (Pb: Z = 82) Use the atomic number for the number of electrons and the periodic table for the order of filling for electron orbitals. Condensed configurations consist of the preceding noble gas and outer electrons. SOLUTION: (a) for K (Z = 19) 1s22s22p63s23p64s1 [Ar] 4s1 There are 18 inner electrons. Barbara A. Gage PGCC CHM 1010
full configuration condensed configuration partial orbital diagram 5s1 4d5 full configuration condensed configuration partial orbital diagram 5p 6s2 6p2 (b) for Mo (Z = 42) 1s22s22p63s23p64s23d104p65s14d5 [Kr] 5s14d5 There are 36 inner electrons and 6 valence electrons. (c) for Pb (Z = 82) 1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p2 [Xe] 6s24f145d106p2 There are 78 inner electrons and 4 valence electrons. Barbara A. Gage PGCC CHM 1010
Configuration for Ions • What is the electron configuration for Na+? Na = 1s22s22p63s1 Na+ = 1s22s22p63s1 • What is the electron configuration for Se2-? Se = 1s22s22p63s23p64s23d104p4 Se2- = 1s22s22p63s23p64s23d104p6 Barbara A. Gage PGCC CHM 1010
Configuration for Ions • Transitions metals have a twist… Fe = 1s22s22p63s23p64s23d6 Fe2+ = 1s22s22p63s23p64s23d6 Fe3+ = 1s22s22p63s23p64s23d5 Barbara A. Gage PGCC CHM 1010