Invisible Ink Experiment Worksheet

Science experiments lesson 13: Lemon juice invisible ink · Set 238 · 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 cotton bud (c) an adult with an iron (d) white paper
2. 2.True or false: cutting the lemon is a job for an adult. (a) True (b) False
3. 3.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the iron setting is the one thing we change. (a) False (b) True
4. 4.🧺 Which of these is not needed for the secret lemon message? (a) yeast (b) a small bowl (c) lemon juice (d) a cotton bud
5. 5.🍋 Which of these steps is a job for an adult? (a) letting the paper dry (b) writing the message (c) reading the message (d) cutting the lemon
6. 6.🧺 Which of these is needed for the secret lemon message? (a) a magnet (b) turmeric powder (c) lemon juice (d) a mirror
7. 7.🔍 Which is the odd one out? (a) cutting the lemon (b) putting the iron away (c) ironing the paper (d) dipping the cotton bud
8. 8.🍋 Secret message: who does this step — dipping the cotton bud? (a) an adult does it (b) a child can do it
9. 9.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is kept the same? (a) the same cotton bud (b) how dark the writing is (c) the kind of juice
10. 10.🧺 Which of these is not needed for the secret lemon message? (a) an adult with an iron (b) white paper (c) a small bowl (d) a magnet
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 same paper (b) the iron setting (c) the kind of juice (d) the same cotton bud
12. 12.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the same paper is the one thing we change. (a) True (b) False
13. 13.🍋 Secret message: who does this step — letting the paper dry? (a) a child can do it (b) an adult does it
14. 14.True or false: lemon juice is not needed for the secret lemon message. (a) True (b) False
15. 15.🔍 Which is the odd one out? (a) letting the paper dry (b) ironing the paper (c) writing the message (d) reading the message
16. 16.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “how dark the writing is”? (a) we change it (b) we keep it the same (c) we measure it
17. 17.True or false: a small bowl is not needed for the secret lemon message. (a) True (b) False
18. 18.🔮 Can the brown writing go back to being invisible? (a) yes, if shaken (b) yes, if cooled (c) no, it stays brown (d) yes, in the dark
19. 19.🍋 Secret message: who does this step — writing the message? (a) a child can do it (b) an adult does it
20. 20.True or false: turmeric powder is needed for the secret lemon message. (a) False (b) True
21. 21.🔍 Which is the odd one out? (a) plugging in the iron (b) letting the paper dry (c) dipping the cotton bud (d) writing the message
22. 22.🔍 Which is the odd one out? (a) letting the paper dry (b) reading the message (c) putting the iron away (d) writing the message
23. 23.🔍 Which is the odd one out? (a) cutting the lemon (b) ironing the paper (c) putting the iron away (d) reading the message
24. 24.🛟 Who should use the hot iron in the secret message experiment? (a) only an adult (b) whoever is fastest (c) the youngest child (d) any child
25. 25.🧺 Do we need a balloon for the secret lemon message? (a) not needed (b) needed
26. 26.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) white paper (b) a mirror (c) lemon juice (d) a cotton bud
27. 27.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? What do we do with “the iron setting”? (a) we keep it the same (b) we change it (c) we measure it
28. 28.🍋 Secret message: who does this step — cutting the lemon? (a) a child can do it (b) an adult does it
29. 29.🧺 Do we need white paper for the secret lemon message? (a) needed (b) not needed
30. 30.🛟 Lemon juice stings cuts and eyes. What should you do after the experiment? (a) wash your hands (b) lick your fingers (c) rub your eyes (d) skip washing
31. 31.True or false: a balloon is needed for the secret lemon message. (a) False (b) True
32. 32.🍋 Which of these steps is a job a child can do? (a) ironing the paper (b) plugging in the iron (c) cutting the lemon (d) dipping the cotton bud
33. 33.🍋 Secret message: who does this step — reading the message? (a) an adult does it (b) a child can do it
34. 34.🔍 Which is the odd one out? (a) putting the iron away (b) cutting the lemon (c) letting the paper dry (d) plugging in the iron
35. 35.🔮 Predict: you write with plain water instead of lemon juice. What appears after ironing? (a) dark brown words (b) a rainbow (c) blue words (d) almost nothing
36. 36.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is what we measure? (a) the ironing time (b) the iron setting (c) how dark the writing is (d) the same cotton bud
37. 37.🧺 Which of these is not needed for the secret lemon message? (a) lemon juice (b) a cotton bud (c) white paper (d) a balloon
38. 38.🔮 Predict: the adult irons for only one second. What happens? (a) it gets darker (b) the paper floats (c) writing turns green (d) writing stays faint
39. 39.🧺 Do we need a small bowl for the secret lemon message? (a) needed (b) not needed
40. 40.🧺 Which of these is needed for the secret lemon message? (a) turmeric powder (b) a cotton bud (c) a balloon (d) a battery cell

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