Atomic structure GapFill

All matter is made up of  ionsatomscellschargesenergymolecules, which come in different types, called  moleculesreactantselementsatomsparticlesmetals, represented using symbols which can be found on the  group seriesreactivity listInternetperiodic tableatomic modelcompound sequence. John Dalton developed his atomic theory, which stated that  atoms can be created and destroyedatoms cannot be broken into smaller partsall atoms are identicalatoms in an element are all uniqueatoms cannot be observedatoms are small, cube-shaped particles.

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  isotopesmoleculesprotonsionselectronsneutrons dotted around...
• Rutherford's model - the  magneticdirectionalelectronicelasticnuclearconnective model - based on the observations of  gamma particlebeta particlealpha particlemetallichalogenradiation scattering...
• Niels Bohr's model, where electrons orbit the  isotopesubatomic particlenucleusmetalsaltion...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  subatomicultrasonicalphaomegamagneticinfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  1211020.5-1, 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  isotopesbondscompoundsionsprotonssalts.