The atom, the fundamental element of matter, is made up of a nucleus surrounded by negatively charged electrons. Contained within the nucleus of the atom is a mixture of positively charged protons and electrically neutral neutrons. All atomic electrons bind to the nucleus through electromagnetic force. A ground of electrons bound together will form individual molecules. An atom with an equal number of protons and electrons will remain neutral. An ion has a positive or negative charge, either due to a lack of electrons or an excess of electrons. The number of protons determines the formation of chemical elements, while the number of neutrons determines the isotope of the element. Most of the atom's mass has a compacted concentration within its nucleus; however, protons and neutrons have approximately the same mass. The electrons bound to atoms contain a percentage of stable energy levels, otherwise called orbitals, which undergo transient processes by absorbing or omitting photons with equal energy levels. Electrons determine the chemical properties of an element, thus influencing the magnetic properties of an atom. Subatomic particles, a scientific term for electrons, protons and neutrons, are the individual atomic components that determine the classification of certain molecules. Electrons have a negative electrical charge that is too small to be measured by modern techniques. Protons have a positive charge with a much greater mass than the electron. Neutrons have no electric charge. Both protons and neutrons have a composition of elementary particles called quarks, a member of the fermionic particle group. Quarks come in six different types, and each has a fractional electric charge. Protons have two up quarks and one down quark, while neutrons have one up quark and two do… half of the article… Matter (PDF): A vast resource detailing the science behind matter all around us , including the composition of atoms and the working motion of all molecules.Miami Science Museum: The Atoms Family: A science project idea illustrating the composition of atoms.New York Hall of Science: All About Molecules: Molecules are small particles that form on all organic and nonorganic matter.SK Online: Atoms and Molecules: A science lesson that explains the fundamental building blocks of life and the composition of all molecules.American Physical Society: From Atoms to Molecules (and Back Again) : Developments in physics have led to laser technology that can combine and break atoms into molecules, and molecules into atoms.4-H Project: Fun with Atoms (PDF): A lesson plan and science project that will help illustrate the composition of atoms in molecules.