Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
state and explain the shapes of, and bond angles in, molecules by using VSEPR theory, including as simple examples: • BF\(_3\) (trigonal planar, 120°) • CO\(_2\) (linear, 180°) • CH\(_4\) (tetrahedral, 109.5°) • NH\(_3\) (pyramidal, 107°) • H\(_2\)O (non-linear, 104.5°) • SF\(_6\) (octahedral, 90°) • PF\(_5\) (trigonal bipyramidal, 120° and 90°)
use dot-and-cross diagrams to illustrate ionic, covalent and coordinate bonding including the representation of any compounds stated in 3.4 and 3.5 (dot-and-cross diagrams may include species with atoms which have an expanded octet or species with an odd number of electrons)
