Water is made up of molecules that consist of two hydrogen atoms covalently bonded to an oxygen atom. The hydrogen an oxygen must be in their most common isotope (this eliminates deuterium oxide). There must be multiple of such molecules (otherwise it would not have the physical properties of water such as being wet) and if we are focusing our definition on liquid water, then the molecules must be moving at a slow enough speed that the entire mass of particles (the water) retains the same volume (water vapor is a gas and so has no fixed volume). We can then see what this definition implies, as in it gives rise to a transparent, tasteless liquid with a density of 1g/cm^3. The resultant liquid from my definition will also react with pure anhydrous copper sulfate to form a blue crystal (this is the chemical test for water). If such a liquid meets the definition and shows the resulting properties, then it is water.

Water is two hydrogen atoms (most common stable isotope) covalently bonded to an oxygen atom (also the most common stable isotope). There must be at least six of such molecules (a hexamer) for it to be water and not just a cluster of water molecules. You can test if this is actually the right substance by seeing if it is a transparent liquid at room temperature. If it is, then you can see if its density is 1g/cm^3 and if a sample of it forms a blue crystal when reacted with anhydrous copper sulfate. If it passes all of those tests, then drink some of the liquid (which was not in the sample reacted with the copper sulfate) and check that it has no taste, refreshes you, and isn’t a poison.

How many molecules of water have to be present before we consider something “wet”?

Water molecules are composed of two hydrogen molecules and an oxygen molecule. Water has many properties to it, such as cohesion, adhesion, surface tension, and high heat capacity. In addition to this water’s solid form is less dense than its liquid form. If a substance were to have these properties then we could say it is water because these properties are unique to water.Side note, these properties of water are essential to life and many result from the hydrogen bonds formed between water molecules.

From a chemistry/atomic perspective water can be defined as two hydrogen atoms bonded to one Oxygen atom, but from another perspective, we can also say that water is the basis for all life. This definition of water assumes that we clearly understand and know that a water molecule is made up of two hydrogen molecules and one oxygen molecule. The second part also assumes that water is the basis for all life on Earth. The definition should clearly isolate water from other potential substances like it. The first part provides a chemical equation of it while the second describes it’s “main use”.

Two Hydrogen Molecules and one Oxygen Molecule come to mind first, but I believe we need to account for its presence and necessity in our lives. The ocean covers more than 70 percent of our planet, and we have explored only an estimated 5 percent. So not only does the ocean, present a operate frontier of exploration, water also operates as the basis of our life.