Answer: binds tightly to haemoglobin.
- A acts as a strong acid
- B binds tightly to haemoglobin
- C acts as a strong base
- D is intensely radioactive
Correct answer: B. binds tightly to haemoglobin
Explanation: CO binds to haemoglobin about 200 times more strongly than O₂, blocking oxygen transport.
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.