Invisible Ink Experiment Worksheet

Science experiments lesson 13: Lemon juice invisible ink · Set 328 · 40 questions

What you do (Heat shows the secret): 1. Dip a cotton bud in lemon juice and write a secret message on white paper. 2. Let the paper dry completely — the writing disappears. 3. An adult irons the paper on a low setting while you watch from a safe distance. 4. Read the brown message and wash your hands.

1. 1.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a battery cell (b) a small bowl (c) a cotton bud (d) lemon juice
2. 2.True or false: a cotton bud is needed for the secret lemon message. (a) False (b) True
3. 3.🍋 Why can’t you see the lemon writing once it dries? (a) it turned into air (b) dry juice is see-through (c) the paper ate it (d) the ink is magnetic
4. 4.🧺 Do we need a magnet for the secret lemon message? (a) not needed (b) needed
5. 5.True or false: writing the message is a job for an adult. (a) True (b) False
6. 6.🛟 Why must children keep their fingers away from the iron? (a) it is cold (b) it is magnetic (c) it can burn skin (d) it is sticky
7. 7.🧺 Do we need a mirror for the secret lemon message? (a) needed (b) not needed
8. 8.🔮 Predict: you write with plain water instead of lemon juice. What appears after ironing? (a) dark brown words (b) almost nothing (c) a rainbow (d) blue words
9. 9.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a small bowl (b) turmeric powder (c) an adult with an iron (d) lemon juice
10. 10.True or false: a magnet is needed for the secret lemon message. (a) True (b) False
11. 11.🍋 Which of these steps is a job for an adult? (a) reading the message (b) plugging in the iron (c) dipping the cotton bud (d) writing the message
12. 12.🍋 Which of these steps is a job for an adult? (a) putting the iron away (b) dipping the cotton bud (c) reading the message (d) writing the message
13. 13.🔍 Which is the odd one out? (a) writing the message (b) dipping the cotton bud (c) ironing the paper (d) reading the message
14. 14.🍋 Which of these steps is a job for an adult? (a) writing the message (b) reading the message (c) cutting the lemon (d) letting the paper dry
15. 15.🔍 Which is the odd one out? (a) plugging in the iron (b) ironing the paper (c) letting the paper dry (d) putting the iron away
16. 16.🧺 Which of these is not needed for the secret lemon message? (a) turmeric powder (b) a cotton bud (c) white paper (d) a small bowl
17. 17.True or false: cutting the lemon is a job a child can do. (a) True (b) False
18. 18.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a balloon (b) white paper (c) lemon juice (d) a small bowl
19. 19.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the iron setting is what we measure. (a) True (b) False
20. 20.🧺 Do we need turmeric powder for the secret lemon message? (a) needed (b) not needed
21. 21.True or false: a battery cell is needed for the secret lemon message. (a) False (b) True
22. 22.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is kept the same? (a) the iron setting (b) how dark the writing is (c) the kind of juice
23. 23.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the same cotton bud is kept the same. (a) True (b) False
24. 24.True or false: a magnet is not needed for the secret lemon message. (a) True (b) False
25. 25.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the same cotton bud is what we measure. (a) True (b) False
26. 26.🍋 Secret message: who does this step — dipping the cotton bud? (a) a child can do it (b) an adult does it
27. 27.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “the same cotton bud”? (a) we change it (b) we keep it the same (c) we measure it
28. 28.🧺 Which of these is needed for the secret lemon message? (a) a magnet (b) a balloon (c) turmeric powder (d) a small bowl
29. 29.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a small bowl (b) lemon juice (c) a mirror (d) a cotton bud
30. 30.🔮 Predict: the adult irons for only one second. What happens? (a) the paper floats (b) writing turns green (c) it gets darker (d) writing stays faint
31. 31.🧺 Do we need a cotton bud for the secret lemon message? (a) not needed (b) needed
32. 32.🍋 Which of these steps is a job a child can do? (a) putting the iron away (b) cutting the lemon (c) letting the paper dry (d) plugging in the iron
33. 33.🛟 Who should use the hot iron in the secret message experiment? (a) whoever is fastest (b) the youngest child (c) only an adult (d) any child
34. 34.🧺 Do we need an adult with an iron for the secret lemon message? (a) needed (b) not needed
35. 35.🍋 Which of these steps is a job a child can do? (a) plugging in the iron (b) ironing the paper (c) writing the message (d) putting the iron away
36. 36.True or false: plugging in the iron is a job for an adult. (a) True (b) False
37. 37.True or false: writing the message is a job a child can do. (a) False (b) True
38. 38.🧺 Which of these is not needed for the secret lemon message? (a) white paper (b) a balloon (c) an adult with an iron (d) a small bowl
39. 39.🧺 Do we need white paper for the secret lemon message? (a) not needed (b) needed
40. 40.🧺 Which of these is needed for the secret lemon message? (a) yeast (b) turmeric powder (c) lemon juice (d) a mirror

Free science experiments lessons, practice and worksheets at talentjr.in/science-experiments-for-kids