Model of the atom GapFill

All matter is made up of  ionsatomsenergycells, which come in different types, called  elementsreactantsparticlesatoms, represented using symbols which can be found on the  periodic tablecompound sequencereactivity listInternet. When these react together,  beta particlesmixturesatomscompounds are formed, which have formulae to show the  percentagepositionratioimportance of each element.  Pure substancesNeutronsElectronsMixtures contain multiple elements or compounds, and can be  meltedshapedseparatedreacted using filtration, distillation, crystallisation and chromatography.

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

• the  dough balldoughnutplum puddingupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalelectronicnuclearconnective model - based on the observations of  gamma particlebeta particlealpha particlemetallic scattering
•  Isaac NewtonMarie CurieNiels BohrNeil Armstrong's model, where electrons orbit the nucleus
•  Dmitri MendeleevJames DaltonCharles DarwinJames Chadwick's model, where neutrons are also in the nucleus

Different  magneticsubatomicinfraredalpha particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  112-110, 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  isotopesprotonssaltsbonds.