Quartz crystals used in clocks are :
- ASodium silicate
- BSilicon dioxide
- CGermanium oxide
- DTitanium dioxide
- ENone of the above/More than one of the above
Show answer and explanation
Correct answer: (b) Silicon dioxide
Explanation
Quartz crystals are silicon dioxide (SiO₂). Quartz is piezoelectric: it vibrates at a steady frequency when a voltage is applied, which keeps time in clocks and watches.
Most quartz used today is grown artificially.