Science 7 · Unit 5: Properties of materials · Cambridge Lower Secondary Science Stage 7

Questions

1. 1. Is "citric acid" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

2. 2. Is "cola" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

3. 3. Is "nitric acid" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

4. 4. Is "sharp" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

5. 5. Is "lemon juice" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

6. 6. Is "sour" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

7. 7. Is "vinegar" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

8. 8. Is "sodium hydroxide" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

9. 9. Is "soap" linked to acids or to alkalis?

   • acids
   • alkalis
   • both
   Check

10. 10. Is "washing powder" linked to acids or to alkalis?

    • acids
    • alkalis
    • both
    Check

11. 11. Is "washing soda" linked to acids or to alkalis?

    • acids
    • alkalis
    • both
    Check

12. 12. Which words can describe both acids and alkalis?

    • corrosive and harmful
    • soap and washing soda
    • citric and nitric
    • sour and sharp
    Check

13. 13. What does the corrosive hazard symbol warn you about?

    • It can burn skin and damage materials.
    • It catches fire easily.
    • It is radioactive.
    • It is safe to touch.
    Check

14. 14. What does the flammable hazard symbol warn you about?

    • It is poisonous to fish.
    • It burns skin.
    • It explodes when wet.
    • It catches fire easily.
    Check

15. 15. Why should you wear safety glasses when using chemicals?

    • to protect your eyes from splashes
    • so the teacher knows you are working
    • to keep your eyes warm
    • to see the chemicals more clearly
    Check

16. 16. Why should you stand up when working with chemicals?

    • so the chairs stay clean
    • so you can see the board
    • to make the reaction faster
    • so you can move away quickly if something spills
    Check

17. 17. Why should you put a bottle stopper upside down on the bench?

    • so it dries faster
    • so the label can be read
    • so the stopper is not contaminated and does not contaminate the bench
    • so it does not roll away
    Check

18. 18. Why should you put the stopper back in a bottle as soon as you have finished with it?

    • so the label does not fade
    • so the next person cannot use it
    • so the bottle cannot spill if knocked over, and fumes cannot escape
    • so the chemical becomes stronger
    Check

19. 19. Why should you work in an orderly way with chemicals?

    • so you finish first
    • so you use more chemicals
    • so the bench looks nice
    • so you don't knock things over or mix up chemicals
    Check