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Are molecules actually 3D? Explain… Some journals now use stereogram's to show molecules in 3D Why do you think it is i

Are molecules actually 3D? Explain… Some journals now use stereogram's to show molecules in 3D Why do you think it is important for chemists to view / understand molecules in 3D?. Empirical evidence for 3D structures ? Electron microscopy and image reconstruction.

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Are molecules actually 3D? Explain… Some journals now use stereogram's to show molecules in 3D Why do you think it is i

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  1. Are molecules actually 3D? Explain… Some journals now use stereogram's to show molecules in 3D Why do you think it is important for chemists to view / understand molecules in 3D?

  2. Empirical evidence for 3D structures? Electron microscopy and image reconstruction

  3. What shape is that molecule? • Empirical evidence • Theoretical evidence (VSEPRT) By the end of the lesson: Standard Level All: Know the names and bond angles of molecules with up to 4 electron pairs around the centre. Most: Predict the molecular shape and electron pair geometry of molecules with up to 4 electron pairs around the centre. Some: Explain the effect of lone pairs on the bond angles in molecules. Higher Level All: Know the names and bond angles of molecules with up to 6 electron pairs around the centre. Most: Predict the molecular shape and electron pair geometry of molecules with up to 6 electron pairs around the centre. Some: Explain the effect of lone pairs on the bond angles in molecules.

  4. Balloon model of valence shell electron pair repulsion theory

  5. Octahedral geometry With 3 balloons • How many electron pairs do we have? • What are the angles between electron pairs? • Invent a name for this shape Why do the balloons fall into this shape? How might this be similar to the behavior of electrons?

  6. Trigonal bipyramidal Two and a half balloons left • How many electron pairs do we have? • What are the angles between electron pairs? • Invent a name for this shape In a real molecule would the chemistry of groups in each of the positions be exactly identical? Explain

  7. Tetrahedral Two balloons remaining • How many electron pairs do we have? • What are the angles between electron pairs? • Invent a name for this shape In a real molecule would the chemistry of groups in each of the positions be exactly identical? Explain

  8. One and a half balloons left Trigonal planar • How many electron pairs do we have? • What are the angles between electron pairs? • Invent a name for this shape What do you think the word ‘planar’ means?

  9. Linear One balloon remaining • How many electron pairs do we have? • What are the angles between electron pairs? • Invent a name for this shape

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