Water-ink travel
Observe ink components travelling with water rather than assume every black marker behaves alike.
Adult planning suggestion: about6–9 · Observation & recall
- Players
- 3–4 per group
- Time
- 20–25 minutes
- Materials
- Two 120×20mm filter-paper strips, water-soluble black markers, shallow water cup, pencil and clips.
Prepare
An adult prepares two equal filter-paper strips. Draw a pencil baseline 15mm from the bottom and add a small water-soluble black marker dot on it. Label the marker brand or sample letter in pencil. Use two brands if available, otherwise record two repeats of one sample. Plain printer paper is not guaranteed to behave like filter paper.
Play
Suspend each strip so the bottom touches about 5mm of water but the ink baseline stays above the water. Keep the strip off the cup wall when practical. Observe as water rises. Use water only in this kit, with no alcohol or other solvents; keep materials out of mouths and wash hands afterward.
Worked example
Mark the water front in pencil when it approaches 90mm from the bottom or after ten minutes, then remove and dry the strip. Record each visible band’s colour and position. One marker may show several bands and another only one; neither outcome is a failed student answer. No particular colour order is promised.
Finish and check
Compare dry strips only after recording paper, water, marker and elapsed time. A submerged starting dot may wash directly into the cup, so flag that run and repeat with the line above the water. Do not identify an unknown chemical or claim purity from a single visual band.
Adaptation and limits
Thirty learners can work in ten trios, sharing adult-prepared cups and rotating dotter, observer and recorder. A drawing of the bands is a free record alternative; it does not replace the filter paper experiment. The ACS activity supports water-based marker separation, while our strip setup and stopping limits are independently chosen.
Purpose, observation and provenance
Within this activity: Observe ink components travelling with water rather than assume every black marker behaves alike.
Check whether a statement is an observation, a prediction or an unsupported identification.
Our rules, examples and printable diagrams are separately prepared. The earliest inventor of the broader mechanism is not established here.
American Chemical Society — Mystery Markers — Water-based dye-separation background; our strip arrangement, dimensions and recording limits are adaptations.
Age bands are planning suggestions. Goals describe observable actions, not measured long-term gains or institutional endorsement.
Free alternative: Copy the supplied grids, labels and cards onto reused paper. No specialist product is needed. Adults may prepare pieces or act as a scribe.
Printable materials
Preview at 100% scale, with browser headers and footers off. Cut with suitable help. Keep host keys separate. This is a manual tabletop kit, not an online opponent, automatic judge or solver.
Player materials · Water-ink travel
FILTER PAPER required; baseline 15mm, water depth about 5mm, stop front 90mm or 10min.
Sample / marker / time / front / bands observed / setup error?
This is a record sheet, not filter paper. Use real filter paper strips; do not replace with this printed sheet.
| Measure | Value |
|---|---|
| Strip | 120×20mm |
| Pencil baseline | 15mm |
| Water depth | ~5mm |
| Stop front/time | 90mm /10min |
Player record · keep host key separate
| Sample/time | Front | Bands | Setup error |
|---|---|---|---|
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
Host key · separate from players
No fixed band count or order. Ink starts above water. One visible band does not prove one pure substance.
Run the round
An adult prepares two equal filter-paper strips. Draw a pencil baseline 15mm from the bottom and add a small water-soluble black marker dot on it. Label the marker brand or sample letter in pencil. Use two brands if available, otherwise record two repeats of one sample. Plain printer paper is not guaranteed to behave like filter paper.
Suspend each strip so the bottom touches about 5mm of water but the ink baseline stays above the water. Keep the strip off the cup wall when practical. Observe as water rises. Use water only in this kit, with no alcohol or other solvents; keep materials out of mouths and wash hands afterward.
Mark the water front in pencil when it approaches 90mm from the bottom or after ten minutes, then remove and dry the strip. Record each visible band’s colour and position. One marker may show several bands and another only one; neither outcome is a failed student answer. No particular colour order is promised.
Compare dry strips only after recording paper, water, marker and elapsed time. A submerged starting dot may wash directly into the cup, so flag that run and repeat with the line above the water. Do not identify an unknown chemical or claim purity from a single visual band.
Thirty learners can work in ten trios, sharing adult-prepared cups and rotating dotter, observer and recorder. A drawing of the bands is a free record alternative; it does not replace the filter paper experiment. The ACS activity supports water-based marker separation, while our strip setup and stopping limits are independently chosen.