2.2.3 Polar and Nonpolar Molecules

• What is a covalent bond formed when atoms share?

  Pairs of electrons
• Electronegativity is a measure of an atom's ability to attract shared electrons in a covalent bond.
• A dipole moment in a polar covalent bond occurs when one end of the bond is partially negative ($δ^{ - }$) and the other end is partially positive
• What is the electronegativity difference required for a polar covalent bond to form?

  Significant
• Nonpolar covalent bonds result in a uniform distribution of charge.
• Atoms with an electronegativity difference of less than 0.4 form nonpolar covalent bonds.
• What is the electronegativity difference range for polar covalent bonds?

  >0.4
• Match the type of intermolecular force with the type of covalent bond:

  Polar Covalent Bond ↔️ Dipole-dipole

  Nonpolar Covalent Bond ↔️ London dispersion forces
• Atoms of the same element always form nonpolar covalent bonds.
• Polar covalent bonds occur when the electronegativity difference is greater than 0.4
• Polar covalent bonds create molecules with no dipoles.

  False
• The primary intermolecular force in nonpolar covalent bonds is London dispersion forces.
• What happens to charge distribution in nonpolar covalent bonds?

  Uniform distribution of charge
• Nonpolar covalent bonds form between atoms of the same element.
• Nonpolar covalent bonds lack a dipole moment.
• Nonpolar covalent bonds are soluble in polar solvents.

  False
• What is the electronegativity difference in polar covalent bonds?

  Significant (>0.4)
• Molecular polarity depends on the overall distribution of charge within a molecule.
• A linear molecule with identical atoms is always polar.

  False
• Order the molecular shapes based on their typical polarity.

  1️⃣ Linear (nonpolar)

  2️⃣ Bent (polar)

  3️⃣ Tetrahedral (nonpolar if identical atoms)

  4️⃣ Trigonal planar (nonpolar if identical atoms)
• Polar molecules have a dipole moment.
• Nonpolar molecules have symmetric shapes.
• What is shared between atoms in a covalent bond?

  Electrons
• Electronegativity is a measure of an atom's ability to attract shared electrons in a covalent bond.
• Higher nuclear charge increases electronegativity.
• Which atom has a higher electronegativity: chlorine or hydrogen?

  Chlorine
• Polar covalent bonds create a dipole moment due to unequal electron sharing.
• Polar covalent bonds result in higher reactivity than nonpolar bonds.
• Why is water a polar molecule?

  Oxygen is more electronegative
• Nonpolar covalent bonds result in a uniform distribution of charge.
• Nonpolar covalent bonds create molecules with significant dipole moments.

  False
• Match the condition with its example for nonpolar covalent bonds:

  Same element ↔️ H_{2}</latex>

  Small electronegativity difference ↔️ $C - H$
• What type of electronegativity difference leads to a nonpolar covalent bond?

  Equal or very similar
• Nonpolar covalent bonds result in a uniform distribution of charge
• Nonpolar covalent bonds produce a significant dipole moment.

  False
• Give an example of atoms of the same element forming a nonpolar covalent bond.

  $H_{2}$
• Atoms of different elements cannot form nonpolar covalent bonds.

  False
• Atoms with electronegativity differences less than 0.4 form nonpolar bonds.
• In what molecule is the $C - H$ bond considered nonpolar?


  $CH_{4}$
• Match the property with its description:

  Lack of dipole moment ↔️ No significant charge separation

  Low reactivity ↔️ Stable and unreactive