2.4.2 Shapes of molecules

• The VSEPR theory states that electron pairs arrange themselves to maximize repulsion.

  False
• Match the molecular shape with its bond angle:

  Linear ↔️ 180°

  Trigonal Planar ↔️ 120°

  Tetrahedral ↔️ 109.5°
• Lone pairs are unshared electron pairs
• What determines the electron domain geometry according to the Electron Domain theory?

  Total number of electron domains
• What is the order of decreasing repulsion strength among electron pairs in a molecule?

  Lone pair-lone pair > lone pair-bond pair > bond pair-bond pair
• The molecular shape is determined by minimizing repulsion
• Match each electron domain geometry with its example:

  Linear ↔️ BeCl₂

  Trigonal Planar ↔️ BF₃

  Tetrahedral ↔️ CH₄
• Linear geometry occurs when a central atom has 2 electron domains
• The bond angle in linear geometry is 180°.


  True
• What are bond pairs in a molecule?

  Shared electron pairs
• The VSEPR theory predicts that lone pair-lone pair repulsion is stronger than bond pair-bond pair repulsion.


  True
• The Electron Domain theory states that electron pairs arrange around the central atom to minimize repulsion
• Electron pairs in a molecule arrange to maximize attraction

  False
• What is an example of a molecule with linear geometry?

  BeCl₂
• What determines the three-dimensional arrangements of atoms within molecules?

  Repulsion between electron pairs
• The repulsion strength between electron pairs follows the order: lone pair-lone pair > lone pair-bond pair > bond pair-bond pair
• Order the steps in the VSEPR theory to determine molecular shape:

  1️⃣ Identify the central atom

  2️⃣ Count the number of electron pairs (bond pairs and lone pairs)

  3️⃣ Determine the electron domain geometry

  4️⃣ Adjust the geometry for lone pairs
• Lone pair-lone pair repulsion is stronger than lone pair-bond pair repulsion.


  True
• Match the number of electron domains with the corresponding geometry:

  2 ↔️ Linear

  3 ↔️ Trigonal Planar

  4 ↔️ Tetrahedral
• Match each molecular shape with its bond angle:

  Linear ↔️ 180°

  Trigonal Planar ↔️ 120°

  Tetrahedral ↔️ 109.5°

  Trigonal Pyramidal ↔️ 107°

  Bent ↔️ 104.5°
• What is the primary goal of the electron domain theory?

  Minimize repulsion
• Lone pairs can distort bond angles in a molecule.


  True
• Which molecule is an example of linear geometry?

  CO₂
• The Valence Shell Electron Pair Repulsion (VSEPR) theory states that electron pairs arrange to minimize repulsion
• What are lone pairs in a molecule?

  Unshared electron pairs
• Steps in determining molecular shape using VSEPR theory

  1️⃣ Determine the central atom

  2️⃣ Count the number of bond pairs and lone pairs

  3️⃣ Arrange electron pairs to minimize repulsion

  4️⃣ Identify the molecular shape
• What determines the electron domain geometry of a molecule?

  Total electron domains
• The electron domain geometry for a molecule with two electron domains is linear
• BF₃ has a trigonal planar geometry


  True
• What is the bond angle in a tetrahedral molecule?

  109.5°
• Linear geometry occurs when a central atom has 2 electron domains, resulting in a bond angle of 180°
• A linear molecule has only bond pairs and no lone pairs


  True
• What is the bond angle in a trigonal planar molecule?

  120°
• Which molecule is an example of tetrahedral geometry?

  CH₄
• What is an example of a molecule with trigonal bipyramidal geometry?

  PCl₅
• Trigonal bipyramidal geometry has a trigonal planar arrangement in the equatorial positions and two bond pairs in the axial positions.


  True
• What is the Valence Shell Electron Pair Repulsion (VSEPR) theory based on?

  Minimizing electron pair repulsion
• The molecular shape is determined by minimizing repulsion between electron pairs.


  True
• What is the order of repulsion strength between electron pairs according to VSEPR theory?

  Lone pair-lone pair > lone pair-bond pair > bond pair-bond pair
• Lone pairs exert stronger repulsion than bond pairs.

  True