Invisible Ink Experiment Worksheet

Science experiments lesson 13: Lemon juice invisible ink · Set 697 · 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.🧺 Which of these is not needed for the secret lemon message? (a) lemon juice (b) white paper (c) an adult with an iron (d) a magnet
2. 2.🍋 Which of these steps is a job for an adult? (a) dipping the cotton bud (b) writing the message (c) plugging in the iron (d) letting the paper dry
3. 3.⚖️ 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 measure it (c) we keep it the same
4. 4.🍋 What colour does the lemon writing turn when an adult warms it? (a) green (b) white (c) brown (d) blue
5. 5.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) white paper (b) a battery cell (c) lemon juice (d) a cotton bud
6. 6.True or false: ironing the paper is a job a child can do. (a) True (b) False
7. 7.🧺 Which of these is not needed for the secret lemon message? (a) lemon juice (b) white paper (c) a balloon (d) a small bowl
8. 8.🔮 Predict: the adult irons for only one second. What happens? (a) the paper floats (b) writing stays faint (c) writing turns green (d) it gets darker
9. 9.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a small bowl (b) an adult with an iron (c) yeast (d) lemon juice
10. 10.🧺 Which of these is needed for the secret lemon message? (a) a small bowl (b) yeast (c) a battery cell (d) a mirror
11. 11.True or false: a magnet is not needed for the secret lemon message. (a) True (b) False
12. 12.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the same cotton bud is kept the same. (a) False (b) True
13. 13.🍋 Which of these steps is a job for an adult? (a) dipping the cotton bud (b) cutting the lemon (c) letting the paper dry (d) reading the message
14. 14.🍋 Which of these steps is a job a child can do? (a) writing the message (b) putting the iron away (c) ironing the paper (d) cutting the lemon
15. 15.🧺 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
16. 16.🧺 Do we need a battery cell for the secret lemon message? (a) not needed (b) needed
17. 17.🔍 Which is the odd one out? (a) cutting the lemon (b) putting the iron away (c) ironing the paper (d) writing the message
18. 18.🧺 Do we need turmeric powder for the secret lemon message? (a) needed (b) not needed
19. 19.🍋 Secret message: who does this step — cutting the lemon? (a) a child can do it (b) an adult does it
20. 20.⚖️ 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) True (b) False
21. 21.🛟 Why must children keep their fingers away from the iron? (a) it is sticky (b) it is cold (c) it is magnetic (d) it can burn skin
22. 22.⚖️ 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
23. 23.🔍 Which is the odd one out? (a) plugging in the iron (b) letting the paper dry (c) reading the message (d) dipping the cotton bud
24. 24.🍋 Which of these steps is a job a child can do? (a) dipping the cotton bud (b) ironing the paper (c) cutting the lemon (d) plugging in the iron
25. 25.⚖️ 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
26. 26.🧺 Which of these is needed for the secret lemon message? (a) turmeric powder (b) yeast (c) a balloon (d) a cotton bud
27. 27.🍋 Secret message: who does this step — dipping the cotton bud? (a) a child can do it (b) an adult does it
28. 28.True or false: white paper is not needed for the secret lemon message. (a) False (b) True
29. 29.🧺 Do we need a small bowl for the secret lemon message? (a) needed (b) not needed
30. 30.🧺 Do we need a mirror for the secret lemon message? (a) not needed (b) needed
31. 31.🍋 Which of these steps is a job for an adult? (a) dipping the cotton bud (b) putting the iron away (c) letting the paper dry (d) reading the message
32. 32.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the ironing time is the one thing we change. (a) False (b) True
33. 33.🍋 Secret message: who does this step — letting the paper dry? (a) an adult does it (b) a child can do it
34. 34.🛟 Lemon juice stings cuts and eyes. What should you do after the experiment? (a) rub your eyes (b) wash your hands (c) skip washing (d) lick your fingers
35. 35.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: how dark the writing is is what we measure. (a) False (b) True
36. 36.True or false: plugging in the iron is a job a child can do. (a) False (b) True
37. 37.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a cotton bud (b) white paper (c) a balloon (d) lemon juice
38. 38.⚖️ 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 keep it the same (c) we measure it
39. 39.📘 The browning of lemon juice with heat is a ___ change. (a) magnetic (b) musical (c) physical (d) chemical
40. 40.🍋 Which of these steps is a job for an adult? (a) dipping the cotton bud (b) letting the paper dry (c) writing the message (d) ironing the paper

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