“Water is a good conductor of electricity”

It's a common belief that water readily conducts electricity, a notion that has led to countless warnings about electronics and water. This widespread assumption, however, is a bit of a half-truth, as the electrical conductivity of water depends almost entirely on what's dissolved within it. Pure water, such as deionized or distilled water, is actually a remarkably poor conductor of electricity.

The scientific evidence points to the presence of ions as the true facilitators of electrical current in water. Water molecules themselves are covalent and do not readily form ions, which are necessary for carrying an electrical charge. However, most water we encounter in daily life—tap water, lake water, or even bottled spring water—contains various dissolved minerals, salts, and other impurities. These substances dissociate into ions when in water, providing the charged particles needed to conduct electricity. For instance, common table salt (sodium chloride) breaks down into sodium ions and chloride ions, which can then carry an electrical current.

People commonly believe water is a good conductor because their everyday experiences reinforce this idea. We are taught from a young age to avoid mixing electricity and water, and for good reason: touching an electrical appliance while wet can indeed be dangerous, even fatal. This danger stems from the fact that the water (Review) we typically interact with, whether from a faucet or a puddle, is never perfectly pure. It always contains enough dissolved ions to make it conductive enough to pose a significant electrical hazard, thus perpetuating the plausible but ultimately inaccurate myth.