Model of the atom GapFill

All matter is made up of  energyatomscellsions, which come in different types, called  elementsreactantsparticlesatoms, represented using symbols which can be found on the  periodic tablecompound sequenceInternetreactivity list. When these react together,  mixturesbeta particlesatomscompounds are formed, which have formulae to show the  ratioimportancepositionpercentage of each element.  MixturesNeutronsElectronsPure substances contain multiple elements or compounds, and can be  shapedseparatedmeltedreacted using filtration, distillation, crystallisation and chromatography.

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

• the  doughnutdough ballplum puddingupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  electronicnucleardirectionalconnective model - based on the observations of  beta particlemetallicgamma particlealpha particle scattering
•  Neil ArmstrongNiels BohrMarie CurieIsaac Newton's model, where electrons orbit the nucleus
•  James DaltonJames ChadwickDmitri MendeleevCharles Darwin's model, where neutrons are also in the nucleus

Different  alphamagneticsubatomicinfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  101-112, 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  isotopessaltsbondsprotons.