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Chapter 8.1-8.3. Basic Concepts of Chemical Bonding. Chemical Bonding. Force of attraction that holds atoms together. Types of Bonds. Metallic bond e - are free to move around the metal atoms e - e.g. Fe,Co, Ni, etc.
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Chapter 8.1-8.3 Basic Concepts of Chemical Bonding
Chemical Bonding • Force of attraction that holds atoms together
Types of Bonds • Metallic bond • e- are free to move around the metal atoms e- • e.g. Fe,Co, Ni, etc. • Metals are shiny • Good conductors of heat & electricity • Malleable
Types of Bonds • Ionic Bond • Bond between (+) and (-) ions. • Ex. NaCl Na+ … Cl- • Covalent Bond • Due to sharing of e-. H•*H H – H
Lattice Energy (LE) • Energy required to separate gaseous ions from a mole of a solid ionic compound. NaCl (s) Na+ (g) + Cl- (g) ∆H latt = 788 kJ/mol
Ionic bond is due to electrostatic attraction. Coulomb's Law: E Q1 Q2 d Q1 - charge on 1st atom Q2 - charge on 2nd atom d - distance between charges Problems: 8.22,25 (P337) Effect of charge & effect of size? LiCl, NaBr, RbBr, MgO
Transition Metal Ions • In forming ions e- is first removed from the outermost s orbital. e.g. Ti (Ar) 4s2 3d2 Ti +2 (Ar) 3d2
Non Transition ion • e- is removed from the outermost orbital (does not have to be a s orbital). e.g. C 1s2 2s22p2 C+ 1s2 2s22p1
Lewis’ Representation of Valence e- Outermost s and p e- . Li 1s22s1 : Ca (Ar) 4s2