Each group needs:

• LEGO MINDSTORMS Education EV3 Core Set (includes color sensor) available at https://education.lego.com/en-us/products/lego-mindstorms-education-ev3-core-set/5003400#lego-mindstorms-education-ev3. If not enough LEGO bricks and sensors are available for each group, conduct the data gathering portion of the activity as a class demonstration, sharing the reflected light data with the class, so students can complete the rest of the activity
• 9 plastic cuvettes, labeled A-G and 1-2, a pack of 100 available at https://www.universalmedicalinc.com/brandtech-brand-polystyrene-spectrophotometry-cuvettes.html?
• ruler
• Pre-Activity Assessment, one per student.
• Determining Concentration Worksheet, one per student
• Post- Activity Assessment, one per student

To share with the entire class:

• red liquid food coloring
• water
• 9 containers, to hold 20 ml of liquid each
• masking tape/pen or wax pencil, to label 9 containers

Note: This activity can also be conducted with the older (and no longer sold) LEGO MINDSTORMS NXT set instead of EV3; see below for those supplies:

• LEGO MINDSTORMS Education NXT Base Set (includes light sensor)