Can Electricity Move Through Water?

Electricity is an invisible yet powerful force that powers our modern world. We flip a switch and a light turns on. We plug in our phones and they recharge. Electricity makes our lives easier and more convenient every day.

Yet for something so commonplace, electricity also holds an air of mystery and danger. We’ve all experienced static shocks from doorknobs or clothing. We know not to stick a fork into an electrical outlet or drop a blowdryer into a filled bathtub. Electricity and water notoriously do not mix, with potentially lethal consequences.

But why exactly is that? Can electricity move through water at all? Are there any conditions where water can conduct electricity safely? Let’s shed some light on this phenomenon.

Table of Contents

Electricity Basics

Electricity is the flow of electric current along a conductor. Electric current is comprised of moving electrons that generate energy. This energy allows electricity to perform work such as powering appliances, transmitting information, or producing light.

Voltage, measured in volts, refers to the electric potential energy per unit charge between two points on a circuit. Current, measured in amperes or amps, is the rate at which the electric charges flow past a point on a circuit. Conductors are materials like metals that allow electricity to flow freely, while insulators like plastic limit or block the flow of electricity.

For electricity to flow, there must be a closed loop or circuit for the electrons to move along. Basic circuits require an energy source to generate voltage, conductive wires to transport current, and a device like a light bulb to utilize the electricity and complete the loop.

Water’s Electrical Properties

Water molecules have a polar structure, meaning they have both positively and negatively charged ends. The oxygen atom in water has a slightly negative charge, while the hydrogen atoms have a slightly positive charge. This gives water some unique properties when it comes to electricity.

Pure water is actually a poor conductor of electricity. The polar molecules make it difficult for electric currents to flow through water easily. However, once salts, minerals and other impurities are dissolved in water, it becomes a much better conductor. That’s because the dissolved ions (atoms with a positive or negative charge) can transport electric current.

Tap water and salt water are examples of impure water that conducts electricity better than pure water. The minerals, salts and metals dissolved in them contain free moving ions that allow current to flow.

Factors That Influence Conduction

Several factors can affect how well electricity is conducted through water, including:

Salinity

The salt content, or salinity, of water significantly impacts conduction. The more dissolved salt is present, the better the water conducts electricity. Seawater has high salinity and is a much better conductor than freshwater.

Solutes

Not only salt, but any dissolved ionic compounds (solutes) will increase conduction. Examples of solutes that allow electricity to pass through water more easily include salts, acids, and bases. The more solutes, the greater the conduction.

Temperature

As temperature rises, the atoms and molecules in water move faster and conduction increases. Heated water conducts better than colder water.

Pressure

Increasing the pressure also supports better conduction through water. At extremely high pressures deep in the ocean, seawater can conduct electricity about as well as copper wire.

Pure vs Tap Water

Pure water, such as distilled or deionized water, is an incredibly poor conductor of electricity. This ultra pure water has no dissolved salts or minerals, which allows it to resist electrical current flow. Tap water and untreated lake or river water, on the other hand, have some levels of dissolved salts and minerals that enable conduction. The more dissolved ions in the water, the more conductive it becomes.

Distilled water is created through a process of evaporation and condensation to remove any dissolved salts or minerals. This results in water containing very low concentrations of ions, and therefore has high resistivity. Deionized water goes through an ion exchange process to remove dissolved ions, also increasing resistivity.

Tap water contains common ions like calcium, magnesium, potassium and sodium that enable electrical current to flow more freely through the water. The concentrations and types of dissolved ions vary based on the water source and treatment processes. Water high in iron content or other dissolved minerals tends to have higher conductivity.

Because of its purity and low ion concentration, distilled water is sometimes used as an insulator in electrical applications. The high resistivity allows it to impede the flow of electricity. Tap water’s lower resistivity allows current to pass through more easily.

Conduction in Living Things

Electricity plays an essential role in the biology of many organisms. Perhaps the most famous example is the electric eel. Electric eels have specialized electrocyte cells that allow them to generate powerful electric discharges up to 860 volts – enough to stun prey or deter predators. The electrocytes work together in a manner similar to batteries in series, building up the voltage. While shocking its prey, the eel uses its electricity sense to locate the target precisely.

The human body also relies on electrical signals for nervous system function. Neurons communicate with each other by propagating electrical impulses called action potentials along their cell membranes. The signals travel down the neural pathways, allowing for rapid transmission of information to the brain and between different parts of the body. This electrochemical signaling allows us to sense stimuli, process information, and coordinate movement.

Overall, the ability of electricity to flow through watery environments enables many living organisms to harness its power in intriguing ways. Both the stunning abilities of electric eels and the complex neural functions in our own bodies depend on water’s conductive properties.

Practical Applications

There are some interesting practical applications that utilize electricity’s ability to flow through water:

Electrofishing refers to the practice of using electric currents passed through water to stun fish before catching them. The electricity temporarily immobilizes the fish through involuntary muscle contractions without seriously harming them. This allows fishing in a more sustainable way since other aquatic life is not disturbed and fish populations are conserved.

There are some risks and safety concerns when electrofishing. The alternating or pulsed direct currents used in electrofishing equipment can be dangerous or even lethal to humans entering the water. Proper circuit protection, grounding, and isolation from the water are critical.

Electrofishing works because electricity can travel through water and affect living organisms. A similar process is used in medicine through Transcutaneous Electrical Nerve Stimulation (TENS) to stimulate nerves and muscles through the skin.

Water Analogies

Water’s ability to conduct electricity can be compared to metals like copper wires. Just as electrons flow through metal wires, electricity can flow through water due to the presence of ions. The level of conductivity depends on water’s resistivity, which is a measure of how strongly it resists electrical flow. Pure water has very high resistivity and does not conduct electricity well. However, dissolved salts and impurities introduce free ions that allow current to flow more easily, lowering resistivity.

In this analogy, pure water is like an insulator while tap water with impurities acts more like a conductor. Just as wires can have varying levels of conductivity depending on their composition, water’s precise conductivity depends on factors like salinity, temperature and hardness. Understanding water as an imperfect conductor helps explain how electricity moves through this ubiquitous liquid.

Experiments To Try

Conducting hands-on experiments is a great way to see electricity moving through water firsthand. Here are some simple activities to try at home using common materials:

Connect a battery to a small light bulb or LED. Submerge both ends of the wires in a glass of water and observe if the bulb lights up. Try adding salt to the water to see the effect on conduction.

Use an ohm meter or multimeter to test the resistance of tap water vs. distilled water. Lower resistance indicates better conduction.
Make a simple electrolysis cell by connecting two pencils lead (graphite) sticks to a 9V battery using wire. Immerse the lead in a shallow container of water and look for tiny bubbles forming on the leads as the water conducts electricity.
Suspend two metal paperclips from the ends of a battery and lower them into a bowl of water. Watch them move toward each other as the electricity flows.

Explore conductivity using play dough, aluminum foil and an LED light. Shape the dough and foil into a circuit and add water to complete it.

Always exercise caution when working with electricity around water. Adult supervision is recommended.

Conclusion

In summary, electricity can absolutely travel through water under the right conditions. While pure H2O is a poor conductor, the minerals and impurities typically found in tap water enable conduction to occur. Factors like voltage, distance between terminals, water volume and temperature all impact the ease with which current can flow. Living creatures like eels demonstrate bioelectrogenesis in their bodies as electrical signals transmit information throughout their nervous systems. Understanding the conductive properties of water has led to innovations like hydroelectric power and medical devices. With proper safety precautions, simple experiments can illustrate electrical current flow using basic materials at home.

The key takeaways are that water can conduct electricity depending on its impurity levels and certain external variables. While pure water itself is an insulator, tap water and saltwater allow the passage of electrical current via the ions present. Conduction also occurs naturally through living organisms reliant on bioelectrical signaling. Overall, water’s versatile conductive properties underpin many important technologies and natural processes.