Model of the atom GapFill

All matter is made up of  ionschargesmoleculesenergycellsatoms, which come in different types, called  reactantsparticlesatomsmoleculeselementsmetals, represented using symbols which can be found on the  periodic tablegroup seriesInternetcompound sequenceatomic modelreactivity list. When these react together,  protonsmixturesatomsbeta particlesnoble gasescompounds are formed, which have formulae to show the  sizepercentagepositionimportanceratiocharge of each element.  MixturesMetalsElectronsHalogensNeutronsPure substances contain multiple elements or compounds, and can be  bondedreactedfusedmeltedshapedseparated using filtration, distillation, crystallisation and chromatography.

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

• the  doughnutplum puddingupside-down pineappledough ballstrawberry shortcakecheesecake model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  connectivenuclearmagneticelectronicelasticdirectional model - based on the observations of  halogenradiationalpha particlegamma particlemetallicbeta particle scattering
•  Neil ArmstrongMarie CurieAlbert EinsteinNiels BohrTheodore RooseveltIsaac Newton's model, where electrons orbit the nucleus
•  Dmitri MendeleevCharles DarwinJames DaltonAlexander FlemingFrancis DrakeJames Chadwick's model, where neutrons are also in the nucleus

Different  omegamagneticalphainfraredsubatomicultrasonic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  102-11120.5, 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  compoundsionssaltsisotopesbondsprotons.