Bonding Lesson #4 v3 (1)

Bonding Review

• Compounds Classification

  • HBr: ________

  • OF2: ________

  • Br2: ________

  • RbBr: ________

  • NaF: ________

  • I2: ________

  • NH4Cl: ________

  • KCl: ________

Metallic Bonding

1. Definition:

   • Occurs between atoms of metals (Na, Au, Cu, Zn, Ac, Be, Gd, Fe).

   • Metals are positive ions in a sea of mobile electrons.

   • Conduct electricity due to free-moving electrons.

2. Properties of Metallic Solids:

   • Good conductors of heat and electricity.

   • Great strength.

   • Good malleability and ductility.

   • Hard and shiny luster.

3. Why Metals Conduct Electricity?

   • Electrons can freely move between metal atoms.

High Melting/Boiling Points

• Metals have high melting and boiling points.

• Explanation of hardness.

Intermolecular Forces

• Groups of covalently bonded atoms attract similar molecules or ions.

Nonpolar Molecules

• Defined as symmetrical molecules (e.g., CH4).

• Diatomic Elements:

  • Molecular formulas: I2, Br2, Cl2, F2, O2, N2, H2

  • Structural formulas: I-I, Br-Br, Cl-Cl, F-F, O=O, N N, H-H

Polar Molecules

• Defined as asymmetrical molecules (e.g., NH3).

• Mnemonic Device:

  • SNAP: Symmetrical = Nonpolar, Asymmetrical = Polar.

• Polar Molecules with Polar Bonds (Dipole-Dipole):

  • Molecular formulas: H2O, H2S, NH3, HF, HCl, HBr, HI.

Hydrogen Bonding

1. Strongest bonds form between hydrogen and high electronegative elements (F, O, N).

   • Examples: HF, H2O, NH3.

2. Accounts for high boiling point of water.

Molecule-Ion Attraction

• Occurs when ionic compounds dissociate in solution (e.g., NaCl(aq), KCl(aq)).

Water and Other Molecules

• Water: Polar molecule.

• Ammonia (NH3): Polar molecule.

• Methane (CH4): Nonpolar molecule.