Atomic structure GapFill

All matter is made up of  chargesionscellsatomsenergymolecules, which come in different types, called  elementsmoleculesparticlesatomsmetalsreactants, represented using symbols which can be found on the  compound sequenceatomic modelreactivity listgroup seriesperiodic tableInternet. John Dalton developed his atomic theory, which stated that  all atoms are identicalatoms cannot be broken into smaller partsatoms are small, cube-shaped particlesatoms can be created and destroyedatoms cannot be observedatoms in an element are all unique.

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  electronsionsprotonsneutronsmoleculesisotopes dotted around...
• Rutherford's model - the  connectivenucleardirectionalmagneticelectronicelastic model - based on the observations of  gamma particlemetallichalogenbeta particlealpha particleradiation scattering...
• Niels Bohr's model, where electrons orbit the  nucleussubatomic particleionisotopesaltmetal...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  subatomicultrasonicmagneticalphainfraredomega particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  -12121010.5, 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  bondssaltsprotonsisotopesionscompounds.