Model of the atom GapFill

All matter is made up of  ionscellsenergyatoms, which come in different types, called  elementsreactantsparticlesatoms, represented using symbols which can be found on the  periodic tableInternetcompound sequencereactivity list. When these react together,  compoundsatomsbeta particlesmixtures are formed, which have formulae to show the  importanceratiopositionpercentage of each element.  ElectronsMixturesNeutronsPure 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  doughnutdough ballplum puddingupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  electronicconnectivenucleardirectional model - based on the observations of  gamma particlebeta particlealpha particlemetallic scattering
•  Marie CurieNeil ArmstrongIsaac NewtonNiels Bohr's model, where electrons orbit the nucleus
•  James DaltonDmitri MendeleevCharles DarwinJames Chadwick's model, where neutrons are also in the nucleus

Different  infraredalphamagneticsubatomic 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  saltsisotopesprotonsbonds.