Model of the atom GapFill

All matter is made up of  atomsenergyionscells, which come in different types, called  reactantsparticleselementsatoms, represented using symbols which can be found on the  periodic tablecompound sequencereactivity listInternet. When these react together,  beta particlesatomscompoundsmixtures are formed, which have formulae to show the  percentageratiopositionimportance of each element.  MixturesPure substancesNeutronsElectrons contain multiple elements or compounds, and can be  shapedmeltedseparatedreacted using filtration, distillation, crystallisation and chromatography.

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

• the  plum puddingdoughnutdough ballupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  directionalconnectiveelectronicnuclear model - based on the observations of  beta particlemetallicgamma particlealpha particle scattering
•  Niels BohrMarie CurieNeil ArmstrongIsaac Newton's model, where electrons orbit the nucleus
•  Charles DarwinDmitri MendeleevJames ChadwickJames Dalton's model, where neutrons are also in the nucleus

Different  subatomicinfraredmagneticalpha particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  11210-1, 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  protonssaltsisotopesbonds.