Science / Biology / Proton: A subatomic particle in the nucleus of an atom that carries a positive charge. The positively charged (+1) subatomic particle located in the atomic nucleus and having a mass slightly less than that of a neutron. Elements differ by the number of protons in their atoms.

Proton Donor

Science / Chemistry / Proton Donor: Because a free H+ ion is technically a bare proton, acids are sometimes referred to as 'proton donors' because they release hydrogen ions in solution. The term 'proton donor' is misleading, since in a MORE


Science / Chemistry / Deuterium: (D, 2H) An isotope of hydrogen that contains one neutron and one proton in its nucleus. MORE

Mass Number

Science / Chemistry / Mass Number: The total number of protons and neutrons in an atom or ion. In nuclide symbols the mass number is given as a leading superscript. In isotope names (e. G. Carbon-14, sodium-23) the mass number is the n MORE


Science / Chemistry / Isotone: One of a group of atoms or ions with nuclei that contain the same number of neutrons but different numbers of protons. MORE

Beta Particle

Science / Chemistry / Beta Particle: (ß-) An electron emitted by an unstable nucleus, when a neutron decays into a proton and an electron. In some cases, beta radiation consists of positrons ('antielectrons' which are identical to elect MORE


Science / Chemistry / Nucleon: A proton or a neutron in the atomic nucleus. MORE