Model of the atom GapFill

All matter is made up of  atomscellschargesenergymoleculesions, which come in different types, called  elementsmetalsmoleculesreactantsatomsparticles, represented using symbols which can be found on the  compound sequenceperiodic tablegroup seriesatomic modelInternetreactivity list. When these react together,  noble gasesmixturescompoundsprotonsbeta particlesatoms are formed, which have formulae to show the  sizeimportancepercentageratiopositioncharge of each element.  MixturesElectronsPure substancesHalogensNeutronsMetals contain multiple elements or compounds, and can be  separatedshapedbondedmeltedfusedreacted using filtration, distillation, crystallisation and chromatography.

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

• the  dough ballupside-down pineappledoughnutcheesecakestrawberry shortcakeplum pudding model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  electronicnuclearconnectiveelasticdirectionalmagnetic model - based on the observations of  alpha particleradiationgamma particlehalogenmetallicbeta particle scattering
•  Theodore RooseveltMarie CurieIsaac NewtonNeil ArmstrongAlbert EinsteinNiels Bohr's model, where electrons orbit the nucleus
•  Francis DrakeCharles DarwinDmitri MendeleevJames ChadwickJames DaltonAlexander Fleming's model, where neutrons are also in the nucleus

Different  infraredalphamagneticultrasonicsubatomicomega particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  10-112120.5, 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  bondsprotonscompoundsionssaltsisotopes.