Symmetry and d-Block Chemistry Flashcards
What is a symmetry operation
Something that transforms an object, so that the result can be superimposed exactly on the original
What are the 5 types of symmetry operations
Rotation Inversion Reflection Rotation-reflection Identity
What are the symmetry operation and element of a rotation about an axis of symmetry
Symmetry operation: rotation
Symmetry element: axis
What does Cn stand for in symmetry terms
It’s the symbol of rotation by 1/n of a revolution
What’s a C2 rotation
A 180-degree rotation about an axis of symmetry e.g. water
What’s a C3 rotation
A 120-degree rotation about an axis of symmetry e.g. CH3Cl
What is a C^2_3/C^-1_3 rotation
When there is a 240-degree clockwise rotation about an axis of symmetry or a 120-degree anticlockwise rotation about an axis of symmetry
What’s a C4 rotation
A 90-degree rotation about an axis of symmetry e.g. XeOF4
True or False: 2x C4 rotations equal a C2 rotation
True
What’s a C6 rotation
A 60-degree rotation about an axis of symmetry e.g. benzene
True or False: 2x C6 (C^2_6) rotations is not the same as a C3 rotation
False
True or False: 3x C6 (C^3_6) rotations is the same as a C2 rotation
True
True or False: 4x C6 rotations is not equivalent to a C^2_3 rotation
False
True or False: benzene has 3 types of C2 rotations
True: C2, C2’, and C2’’
True or False: the rotation with the lowest order axis (smallest n) is denoted as the principle axis when a molecule has more than one rotation axis
False, the highest order axis (largest n) will be the principle axis
