Consider the hydrogen atom. It's made from one proton and one electron. If it becomes ionised by losing its electron, that is, it becomes a cation, H+, it's just a simple, single proton.
Previous Page: Aqueous Solutions & Precipitates
A particularly interesting and useful type of aqueous solution involves acids. ('Useful' if you find being alive useful.)
At the heart of acid-base chemistry is the proton. In ionic bonds electrons get passed around. In acid-base reactions protons get passed around, though that isn't how they are usually described.
| Consider the hydrogen atom. It's made from one proton and one electron. If it becomes ionised by losing its electron, that is, it becomes a cation, H+, it's just a simple, single proton. |
Sulphuric acid has the formula H2SO4. As a pure substance it is a liquid at room temperature, with a propensity to grab on to any water molecule in reach. (NEVER NEVER NEVER add water to sulphuric acid - or to any acid for that matter. The vigour with which sulphuric acid attaches itself to water can be, literally, EXPLOSIVE. All those sulphuric acid particles fighting over a few water molecules creates lots of heat ... instantly. "Do as you oughta', add acid to water.")
Aqueous sulphuric acid, having been made aqueous by adding it SLOWLY to lots of water (in an ice bucket if I'm doing the adding) with lots of stirring, dissociates. You know what associate means; hanging out together. Dissociate is the opposite; breaking apart. H2SO4 dissociates into HSO4- ions and H+ ions (our protons, remember?). This, at least by one widely accepted definition (Brönsted and Lowry), makes it an acid. All COMMON acids have one or more hydrogen atoms that can be dissociated. HCl → H+ + Cl-. HNO3 → H+ + NO3-. Even HSO4- → H+ + SO42-.
Bases, on the other hand, accept protons. The most common base, sodium hydroxide (lye), dissociates to become Na+ and OH- ions. The OH- can combine with a H+ to make... HOH, better known as H2O. Thus the OH- is a base.
Solutions of bases are frequently called basic or alkali, and are historically related to the alkali metals (the first column on the periodic table) in that bases commonly are made from cations of these metals and oxide or hydroxide ions, eg Na2O, KOH. There really isn't much more to tell about bases specifically.