Invisible Ink Experiment Worksheet

Science experiments lesson 13: Lemon juice invisible ink · Set 673 · 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.🧺 Do we need a small bowl for the secret lemon message? (a) needed (b) not needed
2. 2.True or false: a balloon is not needed for the secret lemon message. (a) True (b) False
3. 3.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the same cotton bud is the one thing we change. (a) True (b) False
4. 4.⚖️ 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 ironing time (c) how dark the writing is
5. 5.🍋 Which of these steps is a job for an adult? (a) dipping the cotton bud (b) letting the paper dry (c) ironing the paper (d) writing the message
6. 6.🧺 Which of these is not needed for the secret lemon message? (a) yeast (b) an adult with an iron (c) a small bowl (d) lemon juice
7. 7.🧺 Which of these is needed for the secret lemon message? (a) a magnet (b) a battery cell (c) yeast (d) white paper
8. 8.🛟 Why must children keep their fingers away from the iron? (a) it is magnetic (b) it is sticky (c) it is cold (d) it can burn skin
9. 9.📘 The browning of lemon juice with heat is a ___ change. (a) physical (b) musical (c) magnetic (d) chemical
10. 10.🧺 Which of these is not needed for the secret lemon message? (a) an adult with an iron (b) a balloon (c) white paper (d) a small bowl
11. 11.⚖️ 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
12. 12.True or false: writing the message is a job a child can do. (a) True (b) False
13. 13.🧺 Which of these is not needed for the secret lemon message? (a) lemon juice (b) white paper (c) a cotton bud (d) a battery cell
14. 14.🛟 Who should use the hot iron in the secret message experiment? (a) whoever is fastest (b) any child (c) the youngest child (d) only an adult
15. 15.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? Which of these is the one thing we change? (a) the same cotton bud (b) the kind of juice (c) how dark the writing is (d) the same paper
16. 16.🧺 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) white paper (d) a battery cell
17. 17.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) a cotton bud (b) a balloon (c) an adult with an iron (d) white paper
18. 18.True or false: white paper is not needed for the secret lemon message. (a) False (b) True
19. 19.True or false: plugging in the iron is a job a child can do. (a) True (b) False
20. 20.🍋 What colour does the lemon writing turn when an adult warms it? (a) blue (b) brown (c) white (d) green
21. 21.🧺 Do we need white paper for the secret lemon message? (a) not needed (b) needed
22. 22.⚖️ Fair test — does lemon juice or orange juice make darker secret writing? True or false: the iron setting is kept the same. (a) True (b) False
23. 23.🧺 Which of these is not needed for the secret lemon message? (a) a magnet (b) a small bowl (c) an adult with an iron (d) a cotton bud
24. 24.🧺 Which of these is needed for the secret lemon message? (a) a battery cell (b) turmeric powder (c) a balloon (d) lemon juice
25. 25.True or false: a small bowl is not needed for the secret lemon message. (a) True (b) False
26. 26.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) lemon juice (b) white paper (c) a mirror (d) an adult with an iron
27. 27.🍋 Which of these steps is a job a child can do? (a) dipping the cotton bud (b) putting the iron away (c) plugging in the iron (d) cutting the lemon
28. 28.🍋 Secret message: who does this step — dipping the cotton bud? (a) an adult does it (b) a child can do it
29. 29.🍋 Secret message: who does this step — reading the message? (a) an adult does it (b) a child can do it
30. 30.🧺 Do we need yeast for the secret lemon message? (a) not needed (b) needed
31. 31.🛟 Lemon juice stings cuts and eyes. What should you do after the experiment? (a) lick your fingers (b) skip washing (c) rub your eyes (d) wash your hands
32. 32.🍋 Secret message: who does this step — cutting the lemon? (a) an adult does it (b) a child can do it
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.True or false: putting the iron away is a job a child can do. (a) True (b) False
35. 35.True or false: a magnet is needed for the secret lemon message. (a) False (b) True
36. 36.🍋 Which of these steps is a job for an adult? (a) reading the message (b) writing the message (c) letting the paper dry (d) putting the iron away
37. 37.🧺 Three of these are needed for the secret lemon message. Which one is NOT needed? (a) yeast (b) a small bowl (c) lemon juice (d) a cotton bud
38. 38.🧺 Which of these is needed for the secret lemon message? (a) turmeric powder (b) a small bowl (c) a battery cell (d) a balloon
39. 39.True or false: cutting the lemon is a job for an adult. (a) True (b) False
40. 40.🔍 Which is the odd one out? (a) ironing the paper (b) letting the paper dry (c) dipping the cotton bud (d) reading the message

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