The negative ion that results when an atom gains one or more electrons.
An electrode at the positively charged end of a supply of electric current.
The smallest particle of an element.
The number of protons in the nucleus of an atom. Since this number is different for each element, elements are listed on the periodic table of elements in order of atomic number.
An electrode at the negatively charged end of a supply of electric current.
The positive ion that results when an atom loses one or more electrons.
A structure, often a metal plate or grid, that conducts electricity, and which is used to emit or collect electriccharge.
A negatively charged particle in an atom.
A term used to describe the pattern formed by orbitals.
A term describing thecharacteristics of an atom that has acquired excess energy.
A term describing the state of an atom at its ordinary energy level.
An atom or atoms that has lost or gained one or more electrons, and thus has a net electric charge.
Atoms that have an equal number of protons, and hence are of the same element, but differ in their number of neutrons.
A subatomic particle that has no electric charge. Neutrons are found in the nucleus of an atom, alongside protons.
The center of an atom, a region where protons and neutrons are located, and around which electrons spin.
A pattern of probabilities regarding the regions that an electron can occupy within an atom in a particular energy state. The orbital, complex and imprecise as it may seem, is a much more accurate depiction of electron behavior than the model once used, which depicted electrons moving in precisely defined orbits around the nucleus, rather as planets move around the Sun.
A chart that shows the elements arranged in order of atomic number. Vertical columns within the periodic table indicate groups or "families" of elements with similar chemical characteristics.
A particle of electromagnetic radiation.
A value indicating the distance that an electron may move away from the nucleus of anatom. This is designated by a whole-number integer, beginning with 1 and moving upward. The higher the number, the further the electron is from the nucleus, and hence the greater the energy in the atom.
A positively charged particle in an atom.
A term describing any property that has only certain discrete values, as opposed to values distributed along a continuum. The quantization of an atom means that it does not have a continuous range of energy levels; rather, it can exist only at certain levels of energy from the ground state through various excitedstates.
In a general sense, radiation can refer to anything that travels in astream, whether that stream be composed of subatomic particles or electromagnetic waves.
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