莫名其妙的量子世界.ppt

* Probability Distribution for the 1s Wave Function * Radial Probability Distribution ? * * Electron Spin Electron spin quantum number (ms) – can be +? or -?. Pauli exclusion principle - in a given atom no two electrons can have the same set of four quantum numbers. An orbital can hold only two electrons, and they must have opposite spins. Spin appears naturally from Dirac’s relativistic treatment of electrons * Orbital Energies When electrons are placed in a particular quantum level, they “prefer” the orbitals in the order s, p, d, and then f. When electrons are placed in a particular quantum level, they “prefer” the orbitals in the order s, p, d, and then f. When electrons are placed in a particular quantum level, they “prefer” the orbitals in the order s, p, d, and then f. Orbitals Filled for Elements in Various Parts of Periodic Table * Two Spin Statesof a Proton in a Large Magnetic Field An MRI Brain Scan Alfred Pasieka/SPL #PRInc-E01694 A Patientin an MRI Machine SIU #212722 * Isotope Natural %Abundance Spin (I) 1H 99.9844 1/2 2H 0.0156 1 11B 81.17 3/2 13C 1.108 1/2 17O 0.037 5/2 19F 100.0 1/2 29Si 4.700 1/2 31P 100.0 1/2 Nuclear Spin and MRI * * * * * * * 莫名其妙的量子世界 『從原子到宇宙』課程第四週 胡維平 國立中正大學化學暨生物化學系 10/06/2011 Colors and Electromagnetic Waves Bands of Electromagnetic Wave * * Types of Spectra * 任何物質都會放出各種頻率的輻射線，也就是電磁波。經驗告訴我們當溫度愈高物質所放出的輻射線愈強，同時所放出的主要電磁波也愈偏向短波長的輻射線。所謂黑體 (Blackbody) 是首先由德國物理學家 Kirchhoff 在1859年所提出的一種理想的輻射放射物體，它可吸收所有波長的輻射線並在其內部達成完美的熱平衡。此種物體所放出的輻射線種類與強度只與其溫度有關而 與所組成的物質種類無關。宇宙中的恆星如太陽的輻射性質也與理想的黑體十分接近。 Black-Body Radiation * 奧地利物理學家 Josef Stefan在1879年指出黑體輻射的總能量與絕對溫度的四次方成正比，這後來被稱為 Stefan-Boltzmann law: R = s T4 實驗上 s = 5.67 ? 10-8 W/m2-?K4 在1894年時德國物理學家Wilhelm Wien也發現最強的輻射波長與絕對溫度成反比關係，這後來被稱為Wien displacement law: lmax T = 2.898 ? 10-8 m-?K * * * * Cosmic Microwave Background Discovered in 1964 by Arno Penzias and Robert Wilson in Bell Laboratory. (1978 Nobel Prize) Smooth with very small variation 十九世紀末時科學家包括 Wien 及 Rayleigh 等人嘗試以古典