Faraday's Butterfly Net Electricity & Magnetism_Circuits and lead with densities from

and lead with densities from 2

sized so that students can compare its uniform-curvature surface charge against sphere and cone partners in the conductor set

and pith for stem anatomy and plant tissue teaching

the shared mass isolating volume and density as the distinguishing variables across metals and polymers

Acrylic bell-in-vacuum jar with an internal 4-6V DC electric bell that fades and falls silent as the enclosed air is removed

Faraday's Butterfly Net Electricity & Magnetism_Circuits and lead with densities fromDemonstrates that charge resides only on the outer surface of a conductor by inverting the charged net inside out and showing the charge transferring to the new outside layer.