MISSION 03 · CHEMISTRY DISCOVERY
Use tiny drops to make a colour-changing signal; the mark appears as it is made, rather than becoming invisible ink.
2 · Follow the Colour Clues
Your new skill: Use a small indicator mark to detect acidity.
Revisit the skill you will reuse: Previous main-path mission
Match the names to your parts before you build. New parts appear when you first need them. You can point, say the name or show a grown-up.
This container holds and mixes liquids. Its mL marks help us measure volume: how much liquid we use.
Look for: Find the scale and the mL label. One millilitre is a small unit of liquid volume.
Before using it: Put it flat, look at the water level from the side and use readable markings. Ask for a measuring cup if the kit marks are unclear.
Your turn: Point to the 10 mL line without adding powder.
A dropper moves a small amount of liquid, one drop at a time.
Look for: Find its squeeze bulb and narrow tip.
Before using it: Squeeze before dipping, release to draw liquid, then press gently. Rinse between samples. Never mouth-pipette. Drop size can vary.
Your turn: Practise three separate drops of clean water into a tray.
This spoon measures a repeatable amount of powder so our comparisons use the same amount.
Look for: Find the kit's supplied measure and its labelled amount. A level spoon is flat across the top.
Before using it: Use the approved kit measure, not a random kitchen spoon. Powder amount and spoon size must match the kit batch instructions.
Your turn: Show the difference between level and heaped using an empty spoon and a drawing.
A mixing stick moves liquid and powder together so we can compare how mixing affects a result.
Look for: Find the clean stirrer named in the materials.
Before using it: Use a clean stick for each sample, or rinse and dry between samples. Never taste it.
Your turn: Rehearse a gentle stir in an empty container without splashing.
Citric acid is our labelled acidic material. Dissolved in water it can change an indicator's colour and react with baking soda.
Look for: Find the sealed container with its correct label. Similar-looking powders are not interchangeable.
Before using it: Use only the stated amount, goggles and adult supervision. Experiment materials are not food. Keep away from eyes and mouth.
Your turn: Read the label with a grown-up before opening it.
These papers give colour clues about acidity. Litmus tells us acid or base clues; pH paper is compared with its matching colour chart.
Look for: Find red or blue litmus, or pH strips with their supplied chart. They are not interchangeable.
Before using it: Use a fresh piece for each sample and read at the stated time. A colour estimate is not an exact laboratory pH or a food safety test.
Your turn: Match an unused strip to its packet and chart.
A video demonstration will appear here when it is ready. You can follow the written step now.
Before we build, match these names to the parts in front of you. Beaker or measuring cup. This container holds and mixes liquids. Its mL marks help us measure volume: how much liquid we use. Find the scale and the mL label. One millilitre is a small unit of liquid volume. Put it flat, look at the water level from the side and use readable markings. Ask for a measuring cup if the kit marks are unclear. Dropper. A dropper moves a small amount of liquid, one drop at a time. Find its squeeze bulb and narrow tip. Squeeze before dipping, release to draw liquid, then press gently. Rinse between samples. Never mouth-pipette. Drop size can vary. Calibrated kit measuring spoon. This spoon measures a repeatable amount of powder so our comparisons use the same amount. Find the kit's supplied measure and its labelled amount. A level spoon is flat across the top. Use the approved kit measure, not a random kitchen spoon. Powder amount and spoon size must match the kit batch instructions. Mixing stick. A mixing stick moves liquid and powder together so we can compare how mixing affects a result. Find the clean stirrer named in the materials. Use a clean stick for each sample, or rinse and dry between samples. Never taste it. Citric acid. Citric acid is our labelled acidic material. Dissolved in water it can change an indicator's colour and react with baking soda. Find the sealed container with its correct label. Similar-looking powders are not interchangeable. Use only the stated amount, goggles and adult supervision. Experiment materials are not food. Keep away from eyes and mouth. Litmus and pH paper. These papers give colour clues about acidity. Litmus tells us acid or base clues; pH paper is compared with its matching colour chart. Find red or blue litmus, or pH strips with their supplied chart. They are not interchangeable. Use a fresh piece for each sample and read at the stated time. A colour estimate is not an exact laboratory pH or a food safety test. Pause and point to the part that will do the main job in this mission. If it is missing or looks different, ask a grown-up before building.
WHAT YOU'LL USE
Kit list: match the named parts to your box and its component cards. Home list: gather these before starting; some may also be supplied in your kit. Reuse components between missions. Stop and ask a grown-up if an essential part or label is missing.
BEFORE YOU BUILD
Wear goggles. Keep the dropper below eye level. Indicator paper and solutions are not food.
YOUR REWARD
PREDICT BEFORE YOU BEGIN
Will one large drop or several tiny drops make a clearer message? Explain your choice.
YOUR CHALLENGE
NEW POWER-UP
Use a small indicator mark to detect acidity.
You have just practised describe gas evidence without chasing a bigger eruption. Now: use a small indicator mark to detect acidity.
BUILD PATH
STEP 1 OF 8
Measure 10 mL of water into the beaker.
A video demonstration will appear here when it is ready. You can follow the written step now.
Measure 10 mL of water into the beaker.
WHAT'S REALLY HAPPENING?
Indicator paper changes colour when an acidic solution touches it. This is a colour-code activity, not an invisible-ink reveal. Use a large dot or symbol if the supplied strip is too small for a letter.
Indicator strips are used to compare water, soil, pools and laboratory samples.
FAIR-TEST CHALLENGE
Make the same symbol twice: once with a weak citric-acid solution and once with a stronger solution approved by the adult. Keep the paper and drop size the same.
WHEN IT DOESN'T WORK YET
WHAT YOU SEE LIKELY REASON TRY THIS FIRST No colour change The strip may not match the solution or may be old. Try a fresh blue litmus or pH strip from the kit. The whole strip becomes wet Too much liquid was used. Use smaller drops and a new dry strip. The letter is hard to recognise The design is too detailed. Choose one large capital letter made from dots.
CLEAN, RESET AND STORE
Discard used indicator paper. Rinse the dropper, beaker and stick, then dry them.
NEXT SKILL
Identify known acid, water and base samples from evidence.