Methods of predicting the arrangement and location of electrons in atoms Electron Arrangement.
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Transcript of Methods of predicting the arrangement and location of electrons in atoms Electron Arrangement.
Methods of predicting the arrangement and location of electrons in atoms
Electron Arrangement
A. Lewis Dot Structures
valence electrons – e– in an atom’s outermost orbitals (in highest energy level) available for bonding; determine the chemical properties of an element
electron-dot structure – consists of element’s symbol surrounded by dots that represent the atom’s valence e–
© 1998 by Harcourt Brace & Company
sp
d (n-1)
f (n-2)
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B. Electron Congifuration
C. Johannesson
S 16e-
Valence Electrons
Core Electrons
1s2 2s2 2p6 3s2 3p4
C. Notations
Longhand Configuration
Shorthand Configuration Go up one row and over to the Noble
Gas. Fill in the remaining e- in each sublevel
like normal.
S 16e- [Ne] 3s2 3p4
[Ar] 4s2 3d10 4p2
Example - Germanium
White Board Examples
Helium (He)Fluorine (F)Nitrogen (N)Aluminum (Al)Sulfur (S)
Homework
Do the Lewis dot structure and long and short hand electron configuration for the following elements: Magnesium (Mg) Silver (Ag) Gold (Au) Bromine (Br) Europium (Eu)
D. Orbital Diagrams
This configuration gives more detail as to where the electrons are located.
orbital – region of high probability of finding e–; maximum of 2 e– per orbital s sublevel = 1 orbital (2 e–) p sublevel = 3 orbitals (6 e–) d sublevel = 5 orbitals (10 e–) f sublevel = 7 orbitals (14 e–)
Ex: Oxygen
E. General Rules
Pauli Exclusion Principle
Each orbital can hold TWO electrons
with opposite spins.
E. General Rules
Hund’s Rule
Within a sublevel, place one e- per orbital before pairing them.
E. General Rules
Aufbau Principle
Electrons fill the lowest energy orbitals first.
White Board Examples
Indium (In)Selenium (Se)Sulfur (S)Aluminum (Al)
Homework
Do the orbital diagram for the following elements: Magnesium (Mg) Bromine (Br) Phosphorus (P) Neon (Ne)