Rutherford’s Model of theAtomRutherford discovered thaturanium emits fast-movingparticles with a positive charge.He called them alpha particles.
Rutherford’s Model of theAtomIn an experiment he charted thepath of alpha particles after theypassed through a thin layer ofgold foil and a number of theparticles were deflected.Many more thanexpected, sometimes by morethan 90°.
Rutherford’s Model of theAtomProved most of an atom isactually empty space!
Rutherford’s Model of theAtomThe positive charge of an atommust be concentrated in a verysmall central area that he calledthe nucleus.
Rutherford’s Model of theAtomFurther experiments determinedthat the positive charge of anatom is by the number ofprotons in the nucleus.
Rutherford’s Model of theAtomEach proton has a charge of +1.
The Bohr Model of theAtom In Bohr’s model, electronsmove with constant speed infixed orbits around thenucleus, like planets around asun.
The Bohr Model of the Atom Electrons gain or lose energywhen they move between orbitsor energy levels. Energy levelsare like stairs on a staircase orshelves in a bookshelf
The Bohr Model of the Atom Evidence for discrete, uniqueenergy levels comes from thelight given off when energy isadded to the atoms of anelement (such as whenfireworks explode or electricityis added to a neon light).
The Bohr Model of the Atom No two elements have thesame set of energy levels, sothe emission pattern can beused to identify the element.
The Bohr Model of the Atom Video” The Niels Bohr Rap
The Electron Cloud Model Video: electron cloud model
The Nature of Science Each scientist was correct for histime and ability to makeobservations. As improvements in technologycame about, each later scientistproved the previous scientist(s)slightly incorrect.
The Nature of Science Now there is a totally differentmodel of the atom from the firstmodel presented by Dalton. Only some of the theories of eachscientist remain. In general…
The Nature of Science As the ability tomake betterobservationsimproves, the newknowledge maysupport or disprovewhat we have heldto be true.
The Nature of Science As the ability to make betterscientific observations improved, Atomic theory changed over time Scientists improved uponprevious scientists theories byproving the correct and disprovingthe incorrect
The Nature of Science From Dalton’s solid sphere thatbonded the same way all thetime… To Thomson’s “Plum Pudding “model of equal amounts ofpositive and negative charges…
The Nature of Science Then Rutherford proved that theequal charges were separated byvast space in a nucleus andorbiting electrons And Bohr gave order to theorbiting electrons saying that theymaintained constant orbits