Model of the atom GapFill

All matter is made up of  ionsatomscellsenergy, which come in different types, called  elementsreactantsatomsparticles, represented using symbols which can be found on the  reactivity listcompound sequenceperiodic tableInternet. When these react together,  beta particlesatomsmixturescompounds are formed, which have formulae to show the  percentageimportancepositionratio of each element.  Pure substancesElectronsNeutronsMixtures contain multiple elements or compounds, and can be  meltedseparatedreactedshaped using filtration, distillation, crystallisation and chromatography.

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

• the  dough ballplum puddingupside-down pineappledoughnut model, where the atom is a ball of positive charge with electrons dotted around
• Rutherford's model - the  nuclearconnectivedirectionalelectronic model - based on the observations of  beta particlealpha particlegamma particlemetallic scattering
•  Neil ArmstrongNiels BohrMarie CurieIsaac Newton's model, where electrons orbit the nucleus
•  Charles DarwinDmitri MendeleevJames DaltonJames Chadwick's model, where neutrons are also in the nucleus

Different  magneticsubatomicalphainfrared particles have different masses and charges. Protons (positive particles) and neutrons (neutral particles) have a mass of  11210-1, 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  bondsisotopesprotonssalts.