system
Given the following post, respond as if you're commenting on Reddit:
human
How is electricity conducted in bodies of water?

We are all familiar with the toaster in the bathtub suicide method, but it got me thinking about how that process works. How exactly is electrical current conducted through water, and how does that relate to the amount of charge/voltage applied to the water and volume of water being effected? What happens if a lake or ocean is struck by lightning?
gpt
Pure water is a very poor conductor and can be considered an insulating material.

However water has the ability to react with and dissolve substances to form ionic species, both negatively and positively charged. This is because in solutions, these substances are at a lower energy state if they either gain or lose electrons from water molecules. Such substances are known as "electrolytes." The best electrolytes tend to be strong acids or strong bases. For example, hydrogen chloride reacts with water to form hydronium (H3O+) ions and chloride (Cl-) ions in a solution known as hydrochloric acid:

HCl(gas) + H2O -----> H3O+ + Cl-

Since these charged ions are able to move and flow through the solution, they are capable to conduct an electric current.  Applying an electric field will cause them to move towards the cathode and the anode depending on their respective charge, and a net electric current will flow. 

Thus, adding even relatively small amount of dissolved substances can vastly increase water's conductivity. Tap water in many areas tends to contain small amounts of dissolved minerals such as dolomite,limestone, gypsum, or trace amounts of salt from local rocks and soil. This makes tap water a modestly good conductor, bud adding an acid would make it even better.

Moreover the human body has a high percentage of liquid water, and that water contains dissolved ions such a sodium, potassium, chloride, bicarbonate, carbonate, hydroxide, and phosphate ions, So living tissues in the body are good conductors. But the outer layer of skin, the stratum corneum, consists mostly of spongy, fibrous, oil soluble (hydrophobic) proteins, saturated fats, and air. This makes it a good insulator.

In fact, it turns out that the individual drift velocity of electrons in metals is not that much different from the drift velocity of individual ionized molecules in an electrolyte. It tends to be on the order of a few mm per second to a few hundred micrometers/sec

While changes in voltage propagate through an electrical circuit at the speed of light, the drift velocity of charge carriers like electrons or ions tend to be very slow.