Electrons in Atoms
Quantum Theory EQ: What is the relationship between energy levels and sublevels?
A. Atomic Orbitals Home for electrons
A. Atomic Orbitals Principal Quantum Number (n) = major energy level (rows in P-Table) Each principal energy level has Energy sublevels (shapes)
S orbital
P orbitals
D orbitals
F orbitals
B. Sublevel Shapes sublevel Shape # of orbitals s Spherical 1 p Peanut 3 d daisy 5 f flower 7
C. Sublevels and “n” The # of energy levels tells you how many sublevels (shapes) you have n # of sublevels Which sublevels? 1 1 1s 2 2 2s 2p 3 3 3s 3p 3d 4 4 4s 4p 4d 4f
D. Sublevels and electrons Each orbital can hold two electrons sublevel # of orbitals # electrons s 1 2 p 3 6 d 5 10 f 7 14
Electron configuration (1) How do you write electron configurations?
A. Orbital Diagrams 1s 2s 2p Show the arrangement of electrons 1st Energy Level 1s 1 shape 2nd Energy Level 2s 2 shapes 2p
B. Rules Electrons fill the lowest energy orbitals first. 1. Aufbau (Build up) Principle Electrons fill the lowest energy orbitals first.
B. Rules 2. Pauli Exclusion Principle Each orbital can hold TWO electrons with opposite spins.
B. Rules 3. Hund’s Rule Within a sublevel, place one e- per orbital before pairing them. WRONG RIGHT
C. Electron Configuration Orbital Diagram 1s 2s 2p O 8e- Ground State Electron Configuration 1s2 2s2 2p4 Ground State = lowest possible energy
e- configuration practice 1 Element e- configuration Bohr Diagram orbital Diagram H He Be F S Cl Mg Si
s p d (n-1) f (n-2) D. Periodic Patterns 1 2 3 4 5 6 7 6 7 © 1998 by Harcourt Brace & Company
D. Periodic Patterns p s d (n-1) f (n-2) © 1998 by Harcourt Brace & Company
1s1 D. Periodic Patterns 1st column of s-block 1st Period s-block Example - Hydrogen 1s1 1st column of s-block 1st Period s-block
D. Periodic Patterns Example: S 1s2 2s2 2p6 3s2 3p4
D. Periodic Patterns Example: Ge 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2
Group Work: Write the e- config for A B C D E # 1 Si N Ca Ne # 2 In I Ru La Sn # 3 Nd Re Rf Pu Ho Person
Noble Gases E. Notation 8A He Ne Ar Kr Xe Rn
E. Notation Example - Ge (Noble gas notation) [Ar] 4s2 3d10 4p2
S 16e- 1s2 2s2 2p6 3s2 3p4 S 16e- [Ne] 3s2 3p4 E. Notation Longhand S 16e- 1s2 2s2 2p6 3s2 3p4 Core Electrons Valence Electrons (inside) (outside) Shorthand (Noble gas configuration) S 16e- [Ne] 3s2 3p4
E. Notation Core electrons Valence electrons
F. Stability Copper EXPECT: [Ar] 4s2 3d9 ACTUALLY: [Ar] 4s1 3d10 1. Full sublevel Copper EXPECT: [Ar] 4s2 3d9 ACTUALLY: [Ar] 4s1 3d10 Copper gains stability with a full d-sublevel.
F. Stability EXPECT: [Ar] 4s2 3d4 ACTUALLY: [Ar] 4s1 3d5 2. Half-Full Sublevel Chromium EXPECT: [Ar] 4s2 3d4 ACTUALLY: [Ar] 4s1 3d5 Cr gains stability with a half-full d-sublevel.
F. Stability
G. Electron Dot Structures Show # valence electrons Ex: Sulfur = [Ne] 3s23p4 It has 6 valence electrons S
e- configuration practice 2 Element E-config (Longhand) Dot structure Noble gas (shorthand) # valence e- N Skip 3 lines Se Skip 4 lines Sr Pd Mo Ag