If water is made from covalent bonds with no ions, why is it a conductor of electricity?
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Pure water doesn’t conduct electricity. It’s the presence of other ions that allows it to conduct electricity.
Pure water is a lousy conductor of electricity. It has some ions since that is exactly what pH measures, but not much. It needs a little contamination of salt ions to be a good conductor of electricity.
Pure water isn’t a good conductor, but most water will contain impurities like dissolved minerals/salts. Those are what make it conductive.
Pure water isn’t a very good conductor. But insofar as it conducts electricity at all, it does so because water *self-ionizes*: water molecules occasionally tug a hydrogen ion off of other water molecules, forming a hydroxide ion and a hydronium ion: 2 H2O <-> OH- + H3O+. At any given time, around [1 in ten million](https://en.wikipedia.org/wiki/Self-ionization_of_water) water molecules in solution is temporarily one of those two ions.
(As an aside, it can do this because water’s bonds aren’t exactly “pure covalent”. Covalent and ionic bonds exist on a spectrum, with totally symmetric covalent bonds [like the nitrogen-nitrogen bond in N2] at one end of the scale and totally ionic ones [like bonds between halogens and alkali metals] on the other, and polar covalent bonds in the middle. Strictly speaking, all bonds have some of both; we just categorize them into those groups because most bonds are strongly on one end or the other. Water, as it happens, is polar covalent, so it hangs out in the middle of that spectrum. On a scale where pure covalent bonds are a 0 and highly ionic bonds are a ~10, water sits at around 3: more covalent than not, but with significant ionic character too.)
Normal water is a very good conductor because it is extremely good at pulling ionic compounds apart into their constituent ions. Table salt, for example, is pulled apart from NaCl -> Na+ and Cl- to such an extent that NaCl basically doesn’t exist at all in solution (it’s virtually all ions). It’s those ions (called “electrolytes” in this context) that make impure water conductive. Since there are far more of these pulled-apart ions than there are self-ionized water molecules, water with any dissolved minerals is much more conductive than pure water.
There are a lot of misunderstanding here. I will try to address as many as I can.
1) Water is made of ions.
Water is very a special material. The attraction between the oxygen atoms and the hydrogen atoms is actually strong enough that a couple of unusual things happen. First, when they are a solid state, the molecules pulls themselves into a much more regular crystal structure than most molecules do. This unusual crystal structure. is why ice is less dense than water and will float on it. Second, In a liquid state, the molecules actually pull each other apart, resulting in liquid water being a mixture of H^+ and OH^- ions.
2) Ions & Bonding don’t determine conductivity.
Generally speaking, the presences of ions and the type of bonding between atoms don’t generally determine how conductive a material is. The electron configurations will determine how an elemental will react with other elements, but conductivity is completely different. The rules for determining it are complex, but a good rule of thumb is elements with an excess of unpaired electrons in their outer shells, but don’t have a good grip on them will make good conductors. This is why several metals make good conductors. Crystal structure is also important. Materials like silicon are semi-conductors. They be induced to have crystal structures with either an excess or lack of atoms in the crystal structure, resulting in materials with more or less conductivity.
3) Everything is a conductor.
Electricity wants to flow between areas of excess of charge to areas with a lack of charge to balance everything out. To do so, it will follow the path of least resistance. Materials with a high conductivity have a low resistance, so electricity will naturally flow through them. However, if the difference in charge is high enough, electricity will pass through high resistance materials. Air is a great of example of this. Air has an extremely low conductivity, low enough that electricity won’t pass through it under normal conditions. However, if enough charge builds up, like happens during a storm, you will get channels of electricity that will allow the charge is flow to the ground. These are lightning bolts.
Now, normally, pure water isn’t a good conductor. It doesn’t have an excess of electrons and it holds on tightly to the electrons it does have, nor doesn’t it have a crystal structure with places with excesses or lacks of charge. This gives a decent resistance, but not an extremely high one do to the free ion mixture. Impure water (and most water is impure) is different. The impurities bond with the ions, creating areas with excess and lack of charge, making it a better conductor. Still not a good one.
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