The Acid rain test kit is great to use in the classroom or for science fairprojects to determine if you have acid rain in your area, Kit Includes: 15ml Low Range pH Indicator, 6 Test tubes, Color Chart
Square Friction Cube With Hook, 4 Surfaces, 2 Inch, Provides Four Surfaces For Exploration Into The Force Of Friction. Each Side Of The 2in Cube Provides A Surface (Wood, Paper, Vinyl, Sandpaper) With A Different Coefficient Of Friction
Double Convex round Lens, Material: Glass, designed for physics and educational uses, Because of their educational use design, there may be minor imperfections that do not affect physical function, for educational use, Size: 100mm focal length, 2in diameter and 16.5mm thick