Invisible Ink Experiment Worksheet

Science experiments lesson 13: Lemon juice invisible ink · Set 546 · 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.True or false: turmeric powder is needed for the secret lemon message. (a) False (b) True
2. 2.🧺 Do we need an adult with an iron for the secret lemon message? (a) needed (b) not needed
3. 3.True or false: white paper is not needed for the secret lemon message. (a) False (b) True
4. 4.🍋 Which of these steps is a job for an adult? (a) writing the message (b) reading the message (c) ironing the paper (d) dipping the cotton bud
5. 5.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the iron setting is kept the same. (a) False (b) True
6. 6.🍋 Which of these steps is a job a child can do? (a) ironing the paper (b) cutting the lemon (c) plugging in the iron (d) letting the paper dry
7. 7.🧺 Do we need a small bowl for the secret lemon message? (a) needed (b) not needed
8. 8.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is kept the same? (a) how dark the writing is (b) the same cotton bud (c) the kind of juice
9. 9.🧺 Do we need lemon juice for the secret lemon message? (a) needed (b) not needed
10. 10.🧺 Which of these is needed for the secret lemon message? (a) a small bowl (b) a magnet (c) a balloon (d) a mirror
11. 11.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is the one thing we change? (a) the iron setting (b) the kind of juice (c) the ironing time (d) the same paper
12. 12.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) an adult with an iron (b) a mirror (c) lemon juice (d) white paper
13. 13.True or false: a small bowl is needed for the secret lemon message. (a) True (b) False
14. 14.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a cotton bud (b) white paper (c) lemon juice (d) a balloon
15. 15.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “the ironing time”? (a) we change it (b) we measure it (c) we keep it the same
16. 16.🍋 Secret message: who does this step — writing the message? (a) an adult does it (b) a child can do it
17. 17.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “the iron setting”? (a) we measure it (b) we keep it the same (c) we change it
18. 18.📘 The browning of lemon juice with heat is a ___ change. (a) chemical (b) musical (c) physical (d) magnetic
19. 19.🧺 Do we need a balloon for the secret lemon message? (a) needed (b) not needed
20. 20.True or false: yeast is not needed for the secret lemon message. (a) False (b) True
21. 21.🍋 Which of these steps is a job a child can do? (a) cutting the lemon (b) ironing the paper (c) putting the iron away (d) writing the message
22. 22.🛟 Who should use the hot iron in the secret message experiment? (a) any child (b) whoever is fastest (c) the youngest child (d) only an adult
23. 23.🧺 Do we need turmeric powder for the secret lemon message? (a) not needed (b) needed
24. 24.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the iron setting is what we measure. (a) False (b) True
25. 25.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is kept the same? (a) the kind of juice (b) the iron setting (c) how dark the writing is
26. 26.🔍 Which is the odd one out? (a) writing the message (b) reading the message (c) letting the paper dry (d) cutting the lemon
27. 27.True or false: yeast is needed for the secret lemon message. (a) False (b) True
28. 28.True or false: a cotton bud is not needed for the secret lemon message. (a) False (b) True
29. 29.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a cotton bud (b) turmeric powder (c) a small bowl (d) lemon juice
30. 30.🔮 Predict: you write with plain water instead of lemon juice. What appears after ironing? (a) a rainbow (b) dark brown words (c) almost nothing (d) blue words
31. 31.🍋 Why can’t you see the lemon writing once it dries? (a) dry juice is see-through (b) the paper ate it (c) it turned into air (d) the ink is magnetic
32. 32.True or false: a small bowl is not needed for the secret lemon message. (a) False (b) True
33. 33.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: how dark the writing is is kept the same. (a) False (b) True
34. 34.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is what we measure? (a) the kind of juice (b) how dark the writing is (c) the same cotton bud (d) the iron setting
35. 35.True or false: dipping the cotton bud is a job a child can do. (a) True (b) False
36. 36.🧺 Which of these is not needed for the secret lemon message? (a) lemon juice (b) a cotton bud (c) white paper (d) turmeric powder
37. 37.🧺 Do we need a magnet for the secret lemon message? (a) not needed (b) needed
38. 38.🍋 Secret message: who does this step — ironing the paper? (a) an adult does it (b) a child can do it
39. 39.🍋 Which of these steps is a job for an adult? (a) plugging in the iron (b) reading the message (c) dipping the cotton bud (d) letting the paper dry
40. 40.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “how dark the writing is”? (a) we measure it (b) we keep it the same (c) we change it

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