Ring and Ball Apparatus with Stand State_Solid Rotation-to-linear gear-rack simple-machine model converting

Rotation-to-linear gear-rack simple-machine model converting circular gear motion into straight-line rack travel

Demonstrates the polarity-sensitive forward-bias behavior of a light-emitting diode on a base with two 4mm terminals

Sodium chloride lattice kit with 27 color-coded gray and green atoms plus 54 connectors for building the full cubic NaCl crystal structure in three dimensions

Compact 150mm black 4mm-stackable lead with nickel-plated split-hollow pins

iron filings

Ring and Ball Apparatus with Stand State_Solid Rotation-to-linear gear-rack simple-machine model convertingStand mounted ring and ball thermal expansion apparatus, dropping freely through the ring when cool but stopped by the ring once flame heating expands the ball.