Model of the atom GapFill

All matter is made up of  ionsmoleculesenergyatomschargescells, which come in different types, called  elementsparticlesmetalsreactantsatomsmolecules, represented using symbols which can be found on the  reactivity listcompound sequenceatomic modelgroup seriesInternetperiodic table. When these react together,  protonsnoble gasesmixturesatomscompoundsbeta particles are formed, which have formulae to show the  ratioimportancepercentagepositionsizecharge of each element.  NeutronsElectronsMixturesMetalsPure substancesHalogens contain multiple elements or compounds, and can be  shapedseparatedreactedmeltedfusedbonded using filtration, distillation, crystallisation and chromatography.

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

• the  plum puddingcheesecakeupside-down pineapplestrawberry shortcakedough balldoughnut model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  nuclearelectronicdirectionalmagneticelasticconnective model - based on the observations of  beta particlemetallichalogenradiationgamma particlealpha particle scattering
•  Albert EinsteinIsaac NewtonNiels BohrNeil ArmstrongTheodore RooseveltMarie Curie's model, where electrons orbit the nucleus
•  James ChadwickJames DaltonFrancis DrakeCharles DarwinDmitri MendeleevAlexander Fleming's model, where neutrons are also in the nucleus

Different  subatomicmagneticalphaultrasonicinfraredomega particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  0.5210112-1, 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  protonsionsisotopescompoundsbondssalts.