Electrical Conductivity
Electrical Conductivity is how easily a material lets electric current pass through it.
A copper pipe lets water rush through freely, while a rubber hose packed with sand slows the flow to almost nothing. Some materials let electric current pass through with ease, while others block it. Metals are like the open pipe — current flows fast and free. Rubber and plastic are like the sand-filled hose — current can barely move.
Explaining electrical conductivity by grade level
Some things let power flow through them. Metals like copper wire do this well. Other things, like rubber, block the flow. You can test this with a battery and a small light bulb.
Projects that explore electrical conductivity
Different materials let electric current pass through them with different ease. In this experiment, you fill beakers with sand, clay, loam, and loam mixed with liquid fertilizer, then measure the current with a milliammeter. The fertilizer-enriched loam conducts the most current by far, showing that soil type changes how easily current flows.
Distilled water and sea water look nearly identical, but they behave very differently when current tries to pass through them. You set up two beakers with copper electrodes — one filled with distilled water, one with sea water — and connect each to a battery, a light bulb, and an ammeter. The voltage stays nearly the same in both beakers. The current, however, jumps from almost zero in distilled water to a level that lights the bulb in sea water. That difference comes from dissolved salt ions, which carry charge through the liquid in a way that pure water simply cannot.