2.7.2

Molecular Shapes

Test yourself

Electron Pairs and Geometry

There is an optimal geometry for every number of electron pairs. The different types of geometry are:

Illustrative background for LinearIllustrative background for Linear ?? "content

Linear

  • If the central atom of a molecule has two electron pairs, it will likely adopt a linear geometry.
  • The bond angle will be 180o.
Illustrative background for Trigonal planarIllustrative background for Trigonal planar ?? "content

Trigonal planar

  • If the central atom of a molecule has three electron pairs, it will likely adopt a trigonal planar geometry.
  • The bond angle will be 120o.
Illustrative background for TetrahedralIllustrative background for Tetrahedral ?? "content

Tetrahedral

  • If the central atom of a molecule has four electron pairs, it will likely adopt a tetrahedral geometry.
  • The bond angle will be 109.5o.
Illustrative background for Trigonal bipyramidalIllustrative background for Trigonal bipyramidal ?? "content

Trigonal bipyramidal

  • If the central atom of a molecule has five electron pairs, it will likely adopt a trigonal bipyramidal geometry.
  • Molecules with this shape have two bond angles:
    • A 120o angle around the equator.
    • A 90o angle from equator to apex.
Illustrative background for OctahedralIllustrative background for Octahedral ?? "content

Octahedral

  • If the central atom of a molecule has six electron pairs, it will likely adopt an octahedral geometry.
  • The bond angle will be 90o.

Jump to other topics

1Structure - Models of the Particulate of Matter

2Structure - Models of Bonding & Structure

3Structure - Classification of Matter

3.1The Periodic Table: Classification of Elements

3.2Periodic Trends

3.3Group 1 Alkali Metals

3.4Halogens

3.5Noble gases, group 18

3.6Functional Groups: Classification of Organic

3.7Functional Group Chemistry

3.8Alkanes

3.9Alcohols

3.10Halogenoalkanes

4Reactivity - What Drives Chemical Reaction?

5Reactivity - How Much, How Fast & How Far?

6Reactivity - The Mechanisms of Chemical Change

7Measurement, Data Processing & Analysis

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