Model of the atom GapFill

All matter is made up of  ionsatomschargesmoleculescellsenergy, which come in different types, called  metalsreactantsmoleculesparticlesatomselements, represented using symbols which can be found on the  group seriesreactivity listatomic modelInternetperiodic tablecompound sequence. When these react together,  noble gasesprotonsmixturesbeta particlesatomscompounds are formed, which have formulae to show the  positionchargeratiosizepercentageimportance of each element.  MetalsPure substancesHalogensMixturesElectronsNeutrons contain multiple elements or compounds, and can be  fusedbondedmeltedshapedreactedseparated using filtration, distillation, crystallisation and chromatography.

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

• the  dough ballcheesecakestrawberry shortcakeplum puddingdoughnutupside-down pineapple model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  nuclearelasticconnectivemagneticdirectionalelectronic model - based on the observations of  halogenalpha particlegamma particlemetallicradiationbeta particle scattering
•  Marie CurieTheodore RooseveltAlbert EinsteinNeil ArmstrongNiels BohrIsaac Newton's model, where electrons orbit the nucleus
•  Dmitri MendeleevJames ChadwickAlexander FlemingCharles DarwinJames DaltonFrancis Drake's model, where neutrons are also in the nucleus

Different  alphamagneticsubatomicomegaultrasonicinfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  1020.5-1121, 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  compoundsprotonsisotopesbondssaltsions.