Atomic structure GapFill

All matter is made up of  energychargesionsatomscellsmolecules, which come in different types, called  particlesreactantsatomsmoleculeselementsmetals, represented using symbols which can be found on the  reactivity listgroup seriesperiodic tableatomic modelcompound sequenceInternet. John Dalton developed his atomic theory, which stated that  atoms in an element are all uniqueatoms are small, cube-shaped particlesatoms cannot be broken into smaller partsatoms cannot be observedatoms can be created and destroyedall atoms are identical.

Over time, different scientists have developed new models of the atom. These include:

• the plum pudding model, where the atom is a ball of positive charge with  moleculeselectronsneutronsprotonsionsisotopes dotted around...
• Rutherford's model - the  connectiveelectronicdirectionalelasticmagneticnuclear model - based on the observations of  beta particlehalogengamma particlealpha particleradiationmetallic scattering...
• Niels Bohr's model, where electrons orbit the  isotopemetalnucleussubatomic particleionsalt...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  ultrasonicmagneticomegasubatomicalphainfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  212-1100.51, and electrons (negative particles) have a very small mass. The relative atomic mass of an atom is the weighted average mass of all of the element's  isotopescompoundssaltsbondsprotonsions.