Model of the atom GapFill

All matter is made up of  ionsatomscellschargesenergymolecules, which come in different types, called  elementsatomsmetalsparticlesmoleculesreactants, represented using symbols which can be found on the  periodic tablereactivity listatomic modelgroup seriesInternetcompound sequence. When these react together,  beta particlesnoble gasesmixturesprotonscompoundsatoms are formed, which have formulae to show the  positionsizeimportancepercentagechargeratio of each element.  MixturesNeutronsElectronsPure substancesMetalsHalogens contain multiple elements or compounds, and can be  bondedseparatedreactedshapedmeltedfused using filtration, distillation, crystallisation and chromatography.

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

• the  upside-down pineappleplum puddingdoughnutdough ballstrawberry shortcakecheesecake model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalelectronicelasticnuclearconnectivemagnetic model - based on the observations of  radiationmetallicbeta particlealpha particlehalogengamma particle scattering
•  Niels BohrTheodore RooseveltIsaac NewtonMarie CurieAlbert EinsteinNeil Armstrong's model, where electrons orbit the nucleus
•  James DaltonAlexander FlemingJames ChadwickCharles DarwinFrancis DrakeDmitri Mendeleev's model, where neutrons are also in the nucleus

Different  subatomicultrasonicmagneticalphaomegainfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  0.5121210-1, 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  isotopesionsprotonssaltscompoundsbonds.