Which has a bond angle of 109.5°? A C (diamond) B C (graphite) C NH₂ D NH₃ - AQA - A-Level Chemistry - Question 8 - 2020 - Paper 3

To determine which molecular structure has a bond angle of 109.5°, we need to consider the geometry of the molecules presented.

1. C (diamond): In diamond, carbon atoms are arranged in a tetrahedral structure, which has bond angles of 109.5°.
2. C (graphite): Graphite consists of sheets of carbon atoms arranged in a planar structure with bond angles of 120°, not 109.5°.
3. NH₂: Amine molecules like NH₂ have a bond angle that deviates from 109.5° due to the presence of lone pairs on nitrogen, generally around 105°.
4. NH₃: Ammonia (NH₃) has a trigonal pyramidal shape with a bond angle of approximately 107°.

Therefore, the correct answer is: C (diamond).