Model of the atom GapFill

All matter is made up of  energyatomsionscells, which come in different types, called  particleselementsreactantsatoms, represented using symbols which can be found on the  compound sequenceInternetreactivity listperiodic table. When these react together,  beta particlesmixturescompoundsatoms are formed, which have formulae to show the  positionimportancepercentageratio of each element.  NeutronsElectronsMixturesPure substances contain multiple elements or compounds, and can be  reactedmeltedshapedseparated using filtration, distillation, crystallisation and chromatography.

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

• the  doughnutupside-down pineappleplum puddingdough ball model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  nuclearconnectiveelectronicdirectional model - based on the observations of  beta particlegamma particlealpha particlemetallic scattering
•  Neil ArmstrongMarie CurieNiels BohrIsaac Newton's model, where electrons orbit the nucleus
•  Charles DarwinJames ChadwickJames DaltonDmitri Mendeleev's model, where neutrons are also in the nucleus

Different  alphainfraredmagneticsubatomic particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  12-1101, 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  isotopessaltsbondsprotons.