Answer: Groups 13 to 18.
- A Groups 13 to 18
- B Groups 1 to 2
- C Groups 3 to 12
- D Groups 1 to 18
Correct answer: A. Groups 13 to 18
Explanation: The p-block consists of Groups 13 through 18, where the outermost electrons enter p orbitals.
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.