Model of the atom GapFill

All matter is made up of  moleculesionschargesatomsenergycells, which come in different types, called  atomsmoleculesparticlesmetalselementsreactants, represented using symbols which can be found on the  reactivity listcompound sequencegroup seriesatomic modelInternetperiodic table. When these react together,  compoundsbeta particlesprotonsnoble gasesmixturesatoms are formed, which have formulae to show the  positionratioimportancesizepercentagecharge of each element.  MixturesElectronsNeutronsMetalsHalogensPure substances contain multiple elements or compounds, and can be  meltedseparatedshapedreactedbondedfused using filtration, distillation, crystallisation and chromatography.

Over time, different scientists have developed new models of the atom. These include:

• the  strawberry shortcakedoughnutdough ballupside-down pineapplecheesecakeplum pudding model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalelasticconnectiveelectronicmagneticnuclear model - based on the observations of  metallichalogenalpha particlegamma particleradiationbeta particle scattering
•  Theodore RooseveltAlbert EinsteinNeil ArmstrongIsaac NewtonMarie CurieNiels Bohr's model, where electrons orbit the nucleus
•  Dmitri MendeleevJames DaltonAlexander FlemingCharles DarwinJames ChadwickFrancis Drake's model, where neutrons are also in the nucleus

Different  omegainfraredmagneticalphaultrasonicsubatomic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  12110-10.52, 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  bondsprotonsisotopesionscompoundssalts.