Answer: Si-O bonds are stronger than C-C bonds due to partial ionic character and high bond energy.
- A Si-O bonds are stronger than C-C bonds due to partial ionic character and high bond energy
- B Silicon is generally a more abundant element in the Earth's crust than carbon in the majority of cases studied
- C They happen to be optically transparent across the visible spectrum as widely reported
- D They possess an unusually low viscosity at high temperature in standard practice under most conditions encountered
Correct answer: A. Si-O bonds are stronger than C-C bonds due to partial ionic character and high bond energy
Explanation: Si-O bond energy is ~450 kJ/mol (very strong); silicone polymers maintain stability at temperatures that would degrade organic polymers.
Diamond's rigid 3D tetrahedral network makes it the hardest natural material, while graphite's flat hexagonal sheets are held together only by weak forces, letting them slide past each other (used as a lubricant and in pencils).
Concept context
Covers the Boron family (Group 13: B, Al) and the Carbon family (Group 14: C, Si, Ge, Sn, Pb). Key topics include Lewis acid behaviour of BF₃, borax bead test, silicates, silicones, allotropes of carbon, and trends in properties down the group.