By Jia Hui
Create an interactive [an experiment to investigate if there are any dyes with known toxic properties in food colouring, F] for [Secondary 1 G3] [Science] students.
 
Grade level: Secondary 1
Student readiness level: Mixed Abilities
 
The simulation is based on: 
·       explain how the constituents of a mixture can be separated based on their physical properties, using the following techniques: paper chromatography
·       investigate the separation of constituents of mixtures based on basic principles involved in the following separation techniques: paper chromatography
 
Known substances include:
New food colouring F
4 other dyes, W, X, Y and Z (toxic properties)

The objective of the simulation is to: Allow students to practice proper technique of paper chromatography and to identify whether an toxic food dye (W,X, Y, Z)is found in the new food colouring, F by comparing the chromatogram of F with those of four other food dye, W, X, Y and Z, which have known toxic properties .
 
While using the simulation, students should experience:Interactive Elements  
 
Setup Phase
Students select and drag each food dye (W, X, Y, Z) and food colouring (F) to designated spots (a cross) on the start line of filter paper to obtain a dark spot of the food dye on the cross.

Chromatography Process 
Students fill virtual basin with water to 2cm depth. Automatically stop the water pouring once the 2cm depth is reached.
Place the filter paper in. The pencil start line should be above the water level. Show the filter paper in the water.
Time-lapse feature allows students to observe separation over several minutes. Increase size of chromatogram so that students can see clearly. The time-lapse should not show back and forth movement. Should be a continuous movement upwards.

Analysis Phase:
Interactive measuring tools to record distances travelled by different dye components
Side-by-side comparison view of all chromatograms
Pattern matching activity where students identify which toxic dye (W, X, Y, or Z) matches components found in food colouring F. Have clear labels.
 
Assessment Features (to have a button for assessment, and a figure of the chromatogram above the input box for student reference)
Answer input box for students to identify which toxic dye is present in F
Immediate feedback with explanation of correct answer
Reset button to repeat experiment
 
Success Criteria: Students successfully identify that food colouring F contains the same dye components as toxic colouring X by comparing chromatogram patterns and spot positions.