Atomic structure definitions
Terms in this set (13)
A particle that is the smallest part of an element that can exist. It consists of protons and neutrons in a nucleus surrounded by electrons.
The number of protons (positively charged particles) in a nucleus.
A code for an element consisting of one, two or sometimes three letters.
A negatively charged particle that surrounds the nucleus in an atom.
The organization of electrons in shells around the nucleus.
Electron shell diagram
A picture that shows the arrangement of electrons in shells around the nucleus.
A substance made of only one type of atom. An element cannot be turned into another element or anything simpler using a chemical reaction. Each atom of an element has the same number of protons.
An atom which has lost or gained an electron to become positively or negatively charged respectively.
The total number of protons and neutrons in the nucleus of an atom. Also called nucleon number.
Positively charged centre of the atom, containing protons and neutrons.
Electrically neutral particle found in the nucleus of most atoms.
A chart in which all the elements are arranged.
Relative atomic mass
The mean mass of an atom of an element, taking into account the masses of all its isotopes, which have been compared to the mass of a carbon atom. The carbon atom has a relative atomic mass of 12