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Az anyag atomi-molekuláris szerkezete. Színképek A spektroszkópia alapja: a fényt komponenseire bontjuk.

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Az előadások a következő témára: "Az anyag atomi-molekuláris szerkezete. Színképek A spektroszkópia alapja: a fényt komponenseire bontjuk."— Előadás másolata:

1 Az anyag atomi-molekuláris szerkezete

2 Színképek A spektroszkópia alapja: a fényt komponenseire bontjuk

3 Folytonos spektrum Vonalas emissziós sp. Vonalas abszorpciós sp.

4 Angstrom svéd (asztro)fizikus: az atomos hidrogén spektruma a látható fény tartományában Négy vonalat észlelt: 410 nm, 434 nm, 486 nm, and 656 nm. Anders Ångström (1817-1874) One of the leading founders of the science of spectroscopy. He was a pioneer, in 1853, to observe and study the spectrum of hydrogen which was the foundation for Balmer´s formula. After leaving the observatory for the professorship in physics at Uppsala university (1858-1874) he continued his spectral research.

5 Balmer (matematika tanár): a H-atom spektrumvonalaira egyszerű képletet talált 1/ = const. (1/2 2 - 1/n 2 ) ahol n = 3,4,5,6 A teljesebb spektrum:

6 Egy példa: a kozmikus háttér spektruma egy blackbody spektrum, ahol a hőmérséklet, T B = 2.725 K Cosmic Microwave Background The CMB has the spectrum of a blackbody. A blackbody spectrum is produced by an isothermal, opaque and non-reflecting object. Usually a cavity with a small hole is used in the laboratory to make an opaque and non-reflective object. Radiation that enters the cavity through the hole will have to bounce off many walls before it returns to the outside, so even if the walls are only somewhat dark, the hole will appear to be completely black. The diagram at right shows such a cavity, with the blue incoming ray being absorbed completely while the red rays show the outgoing thermal radiation. A simple gedanken experiment shows that the spectrum emitted by a blackbody can only depend on its temperature T.blackbody A fekete-test sugárzása

7 A fotoelektromos effektus (2005: Einstein-év) A foton energiája kvantált E = h

8 Az eredeti kísérlet picit más volt, a kollektoron taszító, negatív feszültség In 1902, Lenard studied how the energy of the emitted photoelectrons varied with the intensity of the light.... To measure the energy of the ejected electrons, Lenard charged the collector plate negatively, to repel the electrons coming towards it. Thus, only electrons ejected with enough kinetic energy to get up this potential hill would contribute to the current. Lenard discovered that there was a well defined minimum voltage that stopped any electrons getting through, we'll call it V stop. To his surprise, he found that V stop did not depend at all on the intensity of the light! Doubling the light intensity doubled the number of electrons emitted, but did not affect the energies of the emitted electrons.

9 A H-atom Bohr-féle elmélete Heisenberg és Bohr A Coulomb-törvény, skaláris formában: F = k c q 1 q 2 /r 2 k c = 1/(4πε) ahol ε a vakuum permittivitása. ε = 8.854×10 −12 C 2 N -1 m -2.

10 French physicist best known for the formulation of Coulomb's law, which states that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. Coulombic force is one of the principal forces involved in atomic reactions.Coulomb's law Coulombic force Charles-Augustin de Coulomb born June 14, 1736, Angoulême, France died August 23, 1806, Paris Coulomb spent nine years in the West Indies as a military engineer and returned to France with impaired health. Upon the outbreak of the French Revolution, he retired to a small estate at Blois and devoted himself to scientific research. In 1802 he was appointed an inspector of public instruction. Coulomb developed his law as an outgrowth of his attempt to investigate the law of electrical repulsions as stated by Joseph Priestley of England. To this end he invented sensitive apparatus to measure the electrical forces involved in Priestley's law and published his findings in 1785–89. He also established the inverse square law of attraction and repulsion of unlike and like magnetic poles, which became the basis for the mathematical theory of magnetic forces developed by Siméon-Denis Poisson. He also did research on friction of machinery, on windmills, and on the elasticity of metal and silk fibres. The coulomb, a unit of electric charge, was named in his honour. coulomb Charles-Augustin de Coulomb's torsion balance, from his Mémoires sur l'électricité et le magnétisme (1785–89). Encycl. Britannica

11 Danish physicist Hans Christian Ørsted discovered in 1820 that a magnetic needle is deflected when the current in a nearby wire varies - a phenomenon establishing a relationship between electricity and magnetism. During September and October 1820, Ampère, influenced by Ørsted's discovery, performed a series of experiments designed to elucidate the exact nature of the relationship between electric current-flow and magnetism, as well as the relationships governing the behavior of electric currents in various types of conductors. Among others, Ampère showed that two parallel wires carrying electric currents magnetically attract each other if the currents are in the same direction and repel if the currents are in opposite directions. This experiments led Ampère to formulate his famous law of electromagnetism, called after him Ampère's law, that describes mathematically the magnetic force between two electrical currents.Hans Christian Ørsted André-Marie Ampère (1775-1836), a French physicist, founded the science of electrodynamics now known as electromagnetism

12 Kiemelés tőlem. Consider a subject under a brightfield microscope which has a pattern of detail in which very small opaque objects are separated from one another by a distance equal to their own diameter. The diagram below represents the diffraction which occurs at a single narrow slit, and is used here to illustrate what happens when light passes through the space separating the opaque objects of the above example. Given the approximation that the wavefront of light arriving at this slit from a very distant point source is planar, Huyghens' principle states that along the imaginary line b which represents the wavefront momentarily present between the edges of the slit, each point on b could itself be considered a secondary source of wavelets which radiate from that point. This provides a basis for determining the distribution of the light energy passing through the slit, which, due to interference between the rays, is neither even nor random. EGYETLEN rés is már diffrakciót ad (Fraunhofer) A hullámtermészet lényege: Interferencia-diffrakció

13 Mégegyszer a Fraunhofer-diffrakció:

14 Több rés: a Fraunhofer-kép és az interferencia szuperpoziciája



17 A polarizált fény: rezgés egy síkban

18 H-atomhoz: a FORGATÓNYOMATÉK (ANGULAR MOMENTUM) This demo is to show how angular momentum is conserved by changing the plane of rotation of a spinning, weighted wheel. This is all done while sitting on a stool that rotates.

19 A H-atom

20 2s 2p

21 3s, 3p, 3d. Figyeljük a csomófelületek számát!

22 Szintvonalak (Offenhartz, p90, scannned)

23 Contour plot of the 2p z wave function of the hydrogen atom. The xz-plane is taken for the cross section. Isosurface of the 2p z wave function of the hydrogen atom.

24 Isosurface of the 3d xy wave function of the hydrogen atom. Contour plot The xy-plane is taken for the cross section.

25 Isosurface of the 3d z 2 wave function of the hydrogen atom. Contour plot of the 3d z 2 wave function of the hydrogen atom. The xz-plane is taken for the cross section.

26 Mégegyszer együtt: radiális eloszlás és el. sűrűség

27 A H-atom pályái Ábrázolva valójában  négyzete, vagyis az elektronsűrűség)

28 A periódusos rendszer

29 Tellur és jód helyet cserél...... Sztori: a tellúr magyar “kapcsolata”: Tellurium was discovered in a certain gold ore from Transsylvania. This ore, known as "Faczebajer weißes blättriges Golderz" (white leafy gold ore from Faczebaja) or "antimonalischer Goldkies" (antimonic gold pyrite), was according to professor Anton von Rupprecht "Spießglaskönig" (argent molybdique), containing native Antimony (note). The same ore was analyzed by by Franz Joseph Müller Freiherr von Reichenstein (1742- 1825) (note), chief inspector of mines in Transsylvania, he concluded in 1782 that the ore did not contain Antimony, but that it was Bismuth sulphide (note). A year later he reported that this was erroneous and that the ore contained mainly gold and an unknown metal very similar to Antimony (note). However, Müller was not able to identify this metal. He gave it the name aurum paradoxium or metallum problematicum because it did not show the properties predicted for the Antimony he was expecting.(note)

30 Mengyelejev

31 Elemek egy hengeren 185 éve született Alexadre Émile Béguyer de Chancourtois....... 1820. január 20-án született Párizsban. A francia geológus, Két évvel az első nemzetközi vegyészkonferencia után 1862-ben Chancourtois az atomsúlyok szerint sorba rendezett elemek neveit egy henger palástjára írta fel spirális alakban.

32 The Nobel Prize in Chemistry 1954 "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances" USA California Institute of Technology (Caltech) Pasadena, CA, USA b. 1901 d. 1994 Linus Carl Pauling

33 Pauling eredeti cikke az elektronegativitásról: J. Am. Chem. Soc. 54, 3570-3582 (1932). Elve: ‘normális’ esetben – tiszta kovalens kötés - a kötésenergia additív lenne. Az eltérés (kötéserősödés) a kötés ionos jellegéből fakad, ami a két atom elektronegativitás-különbségének lehet a mértéke Az eredeti cikkben még a hidrogén nulla, s a fluor 2



36 Komplexek a természetben:

37 A heme molekula:

38 vége a 2. résznek

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