Model of the atom GapFill

All matter is made up of  energyionscellsatoms, which come in different types, called  atomselementsparticlesreactants, represented using symbols which can be found on the  Internetreactivity listperiodic tablecompound sequence. When these react together,  atomsbeta particlescompoundsmixtures are formed, which have formulae to show the  positionratiopercentageimportance of each element.  ElectronsNeutronsMixturesPure substances contain multiple elements or compounds, and can be  reactedshapedseparatedmelted using filtration, distillation, crystallisation and chromatography.

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

• the  doughnutplum puddingdough ballupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalnuclearelectronicconnective model - based on the observations of  gamma particlealpha particlemetallicbeta particle scattering
•  Marie CurieNiels BohrIsaac NewtonNeil Armstrong's model, where electrons orbit the nucleus
•  James DaltonJames ChadwickDmitri MendeleevCharles Darwin's model, where neutrons are also in the nucleus

Different  alphasubatomicinfraredmagnetic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  10-1121, 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  isotopesprotonsbondssalts.