“Water conducts electricity”

The common belief that water is an excellent conductor of electricity stems from our everyday experiences and the very real dangers associated with mixing water and electrical appliances. From a young age, we are taught to keep electronics away from water sources like bathtubs and swimming pools, and for good reason: touching an electrical device with wet hands or dropping one into a body of water can lead to severe shocks or electrocution. This constant reinforcement leads many to assume that water itself is inherently and highly conductive.

Scientifically, however, the truth is more nuanced. Pure water, which is just H2O molecules, is actually a very poor conductor of electricity, acting more like an insulator. For electricity to flow through a liquid, there must be mobile charged particles, or ions, present to carry the electrical current. In pure water, there are very few such ions. The water we encounter daily—tap water, lake water, seawater—is far from pure. It contains various dissolved salts, minerals, and other impurities like calcium, magnesium, and sodium chloride. These impurities dissociate into positively and negatively charged ions when dissolved in water, and it is these free-moving ions that enable the water to conduct electricity. The more dissolved ions present, the higher the water's conductivity. For example, distilled water has a very low conductivity (0.5 to 3 µS/cm), while tap water ranges from 50 to 800 µS/cm, and seawater, rich in salts, can be as high as 55,000 µS/cm.

Therefore, people commonly believe the myth because the water they interact with in their daily lives is almost never pure. Our bodies also contain fluids rich in electrolytes, which are conductive, further contributing to the danger when combined with wet conditions. The practical danger is very real, as even a small amount of impurities is enough to make water conductive and dangerous when electricity is involved. It is this ever-present conductivity of "real-world" water that creates the powerful and understandable misconception.