Answer: Metallic character.
- A Catenation tendency
- B Stability of the +4 state
- C Metallic character
- D Electronegativity
Correct answer: C. Metallic character
Explanation: Down Group 14 the elements change from non-metallic carbon to metallic lead, so metallic character increases while catenation and electronegativity decrease.
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.