Intermolecular Forces of Attraction Quiz

Electronegativity and IMFA Overview

• Pauling scale is the most widely used electronegativity scale.
• Intermolecular Forces of Attraction (IMFA) hold atoms within molecules and molecules together.

Types of Intermolecular Forces of Attraction

• London Dispersion Forces

  • Present solely in nonpolar molecules.
  • Weakest type of intermolecular force.

• Dipole-Dipole Forces

  • Occur between polar molecules.
  • Result from the attraction of dipoles in different molecules.

• Hydrogen Bonding

  • Specific type of dipole-dipole force.
  • Occurs when hydrogen is bonded to nitrogen, oxygen, or fluorine.
  • Strongest attraction, exemplified by water (H2O).

• Ionic-Dipole Forces

  • Attractive force between an ion and a neutral polar molecule.
  • Common in solutions like sodium chloride (NaCl) in water.

Identifying Intermolecular Forces

• Determine if a molecule is polar or nonpolar.
• For polar molecules:
  • Check if hydrogen is bonded to nitrogen, oxygen, or fluorine for hydrogen bonding.
  • If not, dipole-dipole forces are present.
• For nonpolar molecules: Only London dispersion forces are present.

Molecular Structure and Polarity

• Molecules consist of atoms bonded together.
• Bond polarity assessed by the electronegativity difference between elements using a provided table.
• Lewis Dot structures can illustrate molecular polarity and types of intermolecular forces.

Atomic Structure

• Protons: positively charged particles located in the nucleus.
• Neutrons: neutral particles also found in the nucleus.
• Electrons: negatively charged particles orbiting outside the nucleus.
• Formula to find neutrons: Atomic Mass – Protons = Neutrons.

Chemical Bonds

• Metallic Bond: Formed between two metals.
• Ionic Bond: Formed between a metal and a non-metal (e.g., NaCl) through electron transfer.
• Covalent Bond: Involves sharing electrons to achieve a stable electron configuration (octet rule).

Types of Covalent Bonds

• Polar Covalent Bond: Unequal sharing of electrons results in partial charges due to differing electronegativities.
• Nonpolar Covalent Bond: Equal sharing of electrons; no charge separation occurs.

Electronegativity Trends

• Electronegativity refers to an atom's ability to attract electrons.
• It increases across a period (left to right) on the periodic table.
• It decreases down a group (top to bottom).