Shapes of Molecules

• What does a charge cloud represent in chemistry?

  Region where electrons are likely found
• From which model does the concept of charge clouds originate?

  Quantum mechanical model of the atom
• How do electrons behave according to the quantum mechanical model?

  They occupy orbitals with specific shapes
• What determines the shape of a molecule?

  Arrangement of charge clouds around the central atom
• What theory explains the shape of molecules?

  Valence Shell Electron Pair Repulsion Theory (VSEPR)
• According to VSEPR, how do electron clouds arrange themselves?

  As far apart as possible to minimize repulsion
• What is the bond angle in a linear molecule?

  180°
• Which molecule is an example of a linear shape?

  Beryllium chloride (BeCl₂)
• What is the bond angle in a trigonal planar molecule?

  120°
• Which molecule is an example of a trigonal planar shape?

  Boron trifluoride (BF₃)
• What is the bond angle in a tetrahedral molecule?

  Approximately 109.5°
• Which molecule is an example of a tetrahedral shape?

  Methane (CH₄)
• What is the bond angle in a trigonal bipyramidal molecule?

  90° and 120°
• Which molecule is an example of a trigonal bipyramidal shape?

  Phosphorus pentachloride (PCl₅)
• What is the bond angle in an octahedral molecule?

  90°
• Which molecule is an example of an octahedral shape?

  Sulfur hexafluoride (SF₆)
• What does it mean for a molecule to 'expand the octet'?

  Central atoms have more than eight electrons
• What is the bond angle in a trigonal pyramidal molecule?

  About 107°
• Which molecule is an example of a trigonal pyramidal shape?

  Ammonia (NH₃)
• What is the bond angle in a bent molecule?

  About 104.5°
• Which molecule is an example of a bent shape?

  Water (H₂O)
• What is the bond angle in a seesaw-shaped molecule?

  Approximately 102° and 86.5°
• Which molecule is an example of a seesaw shape?

  Sulfur tetrafluoride (SF₄)
• What is the bond angle in a T-shaped molecule?

  About 87.5°
• Which molecule is an example of a T-shaped shape?

  Chlorine trifluoride (ClF₃)
• What is the bond angle in a square pyramidal molecule?

  About 90°
• Which molecule is an example of a square pyramidal shape?

  Bromine pentafluoride (BrF₅)
• What is the bond angle in a square planar molecule?

  About 90°
• Which molecule is an example of a square planar shape?

  Xenon tetrafluoride (XeF₄)
• How can VSEPR theory be used to predict molecular shape?

  By determining the central atom and electron clouds
• What is the central atom in CCl₄?

  Carbon (C)
• How many valence electrons does carbon have?

  4 valence electrons
• How many valence electrons does each chlorine atom have?

  7 valence electrons
• How many valence electrons are used in bonding for carbon in CCl₄?

  All four valence electrons
• What is the optimal arrangement for 4 electron clouds according to VSEPR theory?

  Tetrahedral geometry
• What shape is carbon dioxide (CO₂) despite having double bonds?

  Linear shape
• How are double bonds treated in VSEPR theory?

  Like single bonds regarding electron regions
• What shape results from two regions of electron density in CO₂?

  Linear shape with bond angles of 180°