Atomic structure GapFill

All matter is made up of  energycellsmoleculesatomsionscharges, which come in different types, called  particlesmetalsatomsreactantsmoleculeselements, represented using symbols which can be found on the  Internetreactivity listgroup seriescompound sequenceatomic modelperiodic table. John Dalton developed his atomic theory, which stated that  atoms are small, cube-shaped particlesatoms can be created and destroyedatoms in an element are all uniqueall atoms are identicalatoms cannot be observedatoms cannot be broken into smaller parts.

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  ionsisotopesneutronselectronsmoleculesprotons dotted around...
• Rutherford's model - the  electronicelasticnuclearconnectivedirectionalmagnetic model - based on the observations of  halogenmetallicradiationalpha particlebeta particlegamma particle scattering...
• Niels Bohr's model, where electrons orbit the  isotopesaltmetalnucleussubatomic particleion...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  infraredalphaomegamagneticultrasonicsubatomic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  1122100.5-1, 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  isotopesprotonssaltscompoundsbondsions.