History of the Structure of an Atom

Dalton’s Piture of the Atom

atoms of different elements are of a different mass and atoms of the same element are identical and fundamental (nothing smaller, cannot be broken)

What does the Cathode Ray Tube do?

shows if particles have charge

What does JJ Thompson Figure out?

charge to mass ratio, there is a piece of matter smaller than an atom that has negative charge

JJ Thompsons Plum Pudding Model

looks like a chocolate chip cookie, known something is smaller, matter is neutral so must also be positive charged matter, and there is lots of mass in the atom they couldn’t account for

What did Milton’s Oil Drop Experiment do?

it quantified the charge of an election (it is in 1% of the charge given today)

Rutherfod’s Gold Foil Experiment

thought alpha particles would go straight through the gold sheet but some bounced off even though the mass of alpha particles were more so they were being deflected by something→ the nucleolus

Rutherford’s Nuclear Model

proton in the middle, and electrons move in comparitively large regions of space around the nucleolus but if there i all of this empty space then how is matter solid?

what did James Chadwick do?

identified the radiation emitted when Benillyium is bombarded with alpha particles is the neutron of particles with mass equal to proton but with no charge

modern picture of the nucleus?

protons and neutrons in the middle and electrons go around the outside

octet rule

all atoms gain or lose electrons in order to achheive a “full” outer shell. This usually means 8 electrons in an outershell

cantion

positive charged ion

anion

negatively charged ion

what does mass spectrometry allow us to do?

analyze a sample by first vaporizing the matter with heat and then ionizing the sample with a bean of electrons. the ions move through a magnetic field and the heavier particles don’t bend much and the lighter particles bend more