everything you need to know about atoms
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DESCRIPTIONEverything You Need To Know About Atoms. (for this course). Tiny Bits. Before we talk about what atoms are made of and what they can do, you must know: They are VERY light, They are VERY small, There are VAST numbers of them. Bromide Atoms. Hydrogen on Graphene. Crystal Lattice. - PowerPoint PPT Presentation
Everything You Need To Know About Atoms(for this course)
Tiny BitsBefore we talk about what atoms are made of and what they can do, you must know:They are VERY light,They are VERY small,There are VAST numbers of them.
Hydrogen on Graphene
Photograph of a Single Molecule of Pentacene, used in solar cells14 Carbon and 22 Hydrogen atoms
Biggest Tiny PartsNeutrons: N, heaviest, no electrical chargeProtons: P+, slightly less heavy, positive electrical chargeElectrons: e-, much lighter than neutrons or protons, negative electric chargeAll three have a quantum mechanical quality called spin 1/2
Smaller Tiny PartsNeutrinos: nThree kinds: electron ne, muon nm, tau ntWeakly interactiveVERY low mass, no chargeTravel at the speed of light(Well use these a little later)
AtomsAtoms have protons and electrons and, with one exception, neutronsThe simplest atom is hydrogen75% of the universe is hydrogen
Flavors (Isotopes) of Hydrogen:Deuterium (D)--------Tritium (T)
HeliumTwo electrons, two protons, two neutrons24% of the Universe(There is a flavor with only one neutron)
As of June 2011, 114 different elementsBut hydrogen (H) and helium (He) are all we need for the most part
straP yniT tseggiBAntimatter!Negative protons, positive electronsAntineutrons more difficult to explain (antiquarks, CPT symmetrynot really necessary for our study)When matter meets antimatter: annihilation!(Well meet this later also)
PET ScanPositron emission tomography
It Takes Energy To:Remove an electron from an atom:Jam a proton and neutron together to make deuterium (D)Jam an N and a D together to make a tritium (T)Jam two Ts together to get He
E=mc2Except for reactions that involve only electrons, nuclear processes are governed by that famous equationIt says that matter can be converted to lots of energy, and that energy can be transformed into matterMaking He out of H takes a lot of energy, but once its accomplished, you get more energy back
FusionThat last process is a form of fusionNot to be confused with fission (taught in another course)The reaction can be notated this way:T + T -> 4He + 2NI will use this shorthand later on (and remind you of what it means)
Other ExamplesA reaction can emit energy in the form of a photonD + D -> 4He + gA reaction can generate a neutrinoP+ + P+ -> D + e+ + ne
Dont memorize these! They are just examples!
And thats all you need to know about atoms!