Consider the following statements: Glass can be etched or scratched by 1. I. diamond. 2. II. hydrofluoric acid. 3. III. aquilegia. 4. IV. cone, sulphuric acid. Which of these statements are correct?

1. The question asks which of the listed substances can etch or scratch glass. 2. Statement I: Diamond is the hardest known natural material (Mohs hardness 10). Glass typically has a Mohs hardness of 5.5 to 7. Since diamond is much harder than glass, it can easily scratch glass. Statement I is correct. 3. Statement II: Hydrofluoric acid (HF) is known for its ability to react with silicon dioxide (SiO₂), the main component of glass. This reaction dissolves the glass, allowing it to be etched. Statement II is correct. 4. Statement III: Aquilegia is a genus of flowering plants (Columbine). It has no ability to etch or scratch glass. Statement III is incorrect. (Perhaps 'Aqua regia' was intended? Aqua regia dissolves gold and platinum but does not significantly etch glass). 5. Statement IV: Concentrated sulphuric acid (H₂SO₄) is a strong acid and dehydrating agent but does not typically etch or scratch standard silicate glass under normal conditions. Statement IV is incorrect. 6. Therefore, the correct statements are I and II.