Model of the atom GapFill

All matter is made up of  moleculescellsenergyionschargesatoms, which come in different types, called  moleculesmetalselementsreactantsparticlesatoms, represented using symbols which can be found on the  compound sequencereactivity listgroup seriesperiodic tableatomic modelInternet. When these react together,  protonsbeta particlescompoundsnoble gasesatomsmixtures are formed, which have formulae to show the  chargepositionpercentageratiosizeimportance of each element.  Pure substancesMixturesMetalsHalogensElectronsNeutrons contain multiple elements or compounds, and can be  bondedshapedseparatedfusedreactedmelted using filtration, distillation, crystallisation and chromatography.

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

• the  strawberry shortcakeupside-down pineappledough ballplum puddingdoughnutcheesecake model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalelectronicmagneticnuclearconnectiveelastic model - based on the observations of  metallicalpha particlebeta particleradiationgamma particlehalogen scattering
•  Isaac NewtonMarie CurieNeil ArmstrongTheodore RooseveltNiels BohrAlbert Einstein's model, where electrons orbit the nucleus
•  Dmitri MendeleevAlexander FlemingCharles DarwinJames ChadwickFrancis DrakeJames Dalton's model, where neutrons are also in the nucleus

Different  subatomicinfraredmagneticultrasonicomegaalpha particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  10120.5-112, 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  saltscompoundsbondsprotonsisotopesions.