Atomic structure GapFill

All matter is made up of  energyionschargesatoms, which come in different types, called  moleculeselementsreactantsatoms, represented using symbols which can be found on the  periodic tablereactivity listgroup seriesInternet. John Dalton developed his atomic theory, which stated that  atoms cannot be broken into smaller partsatoms cannot be observedall atoms are identicalatoms can be created and destroyed.

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  electronsneutronsionsmolecules dotted around...
• Rutherford's model - the  connectivenuclearelasticelectronic model - based on the observations of  metallicbeta particlehalogenalpha particle scattering...
• Niels Bohr's model, where electrons orbit the  saltisotopenucleusion...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  subatomicomegaultrasonicalpha particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  -1120.51, 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  protonsisotopesionscompounds.