Atomic structure GapFill

All matter is made up of  chargesenergymoleculesionsatomscells, which come in different types, called  metalsmoleculeselementsreactantsatomsparticles, represented using symbols which can be found on the  periodic tablegroup seriesInternetcompound sequencereactivity listatomic model. John Dalton developed his atomic theory, which stated that  atoms can be created and destroyedatoms cannot be observedatoms cannot be broken into smaller partsatoms are small, cube-shaped particlesatoms in an element are all uniqueall 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  neutronsisotopeselectronsionsmoleculesprotons dotted around...
• Rutherford's model - the  directionalconnectiveelectronicnuclearmagneticelastic model - based on the observations of  alpha particlebeta particlemetallichalogengamma particleradiation scattering...
• Niels Bohr's model, where electrons orbit the  metalsubatomic particlenucleusisotopesaltion...
• and James Chadwick's model, where neutrons are also in the nucleus

Different  infraredultrasonicmagneticalphaomegasubatomic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  0.5-1121210, 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  isotopesbondsionssaltsprotonscompounds.