Ions and compounds – PHScale.net

Atoms are made up of neutrons that are neutral and have no charge, protons with a positive charge andelectrons with a negative charge.

An ion is an entity or a group of atoms with a positive or negative charge such as the positively charged hydrogen ion H⁺and thenegatively charged nitrate ion NO₃^–. Negatively charged ions are also calledanionswhile positively charged ions are calledcations.

A compound is something that is made up oftwo or more simple substances. Ammonia NH₃is a compound without a charge.

Atom model

Below it is shown how positively charged protons (yellow) and neutral neutrons constitutes a nucleusin the atom while the negatively charges electrons orbits the nucleus. This is a very simple model of the atom.A more complicated model would include a nucleus surrounded by orbitals with electrons in them orbiting the nucleus.

Web resources

A philosophical approach to atoms
A full course about atoms and ions
Encarta – encyclopedia