This brief entry describes the hydrogen ion, strictly, as the nucleus of a hydrogen atom separated from its accompanying electron. The hydrogen nucleus is made up of a particle carrying a unit positive electric charge, called a proton.

A video tutorial demonstrating how to calculate the pH of a solution given the hydrogen ion concentration. [3:44]

The equivalent is the amount of a substance which will either react or supply with one mole of hydrogen ions and acid-base reactions or do the same with one mole of electrons in a redox reaction.

This video screencast shows how to convert among pH, [H+], pOH and [OH-], providing several examples. [7:30]

A video tutorial introducing the pH scale as a representation of the concentration of protons. [4:45]

A quiz testing your knowledge of acids and bases. Quiz gives immediate feedback on whether your answer was right or wrong with an explanation.

This set of flashcards helps students review 56 terms related to pH and the sources of H+.

This slide show on atomic bonds contains several slides on electron affinity. Other topics include covalent, Sigma and Pi bonds, and atomic bonding in solids.

A detailed description of comets, their distinct parts, and the known comets in our solar system. Links are also provided for additional information on related subjects.