Hydrogen atom energy "levels" Quantum physics provides the tools to compute the values of E1,E2,E3,etc...The results are: En=-13.6/n2 -☑ 3- Energy Level Energy E (eV) -2 1 -13.6 2 -3.4 3 -1.51 4 -0.85 5 -0.54 These results DO DEPEND ON THE TYPE OFATOM OR MOLECULE So,the difference in energy between the 3d and 1st quantum state is: Eim=E3-E1=-1.51-(-13.6)=12.09(cV When this 31 atomic transition occurs,this energy is released in the form of electromagnetic energy. PDF文件使用"pdfFactory”试用版本创建www.fineprint.cn
Hydrogen atom energy “levels” Quantum physics provides the tools to compute the values of E1 , E2 , E3 , etc…The results are: En = -13.6 / n2 Energy Level Energy En (eV) 1 -13.6 2 -3.4 3 -1.51 4 -0.85 5 -0.54 So, the difference in energy between the 3rd and 1st quantum state is: Ediff = E3 – E1 = -1.51 – (-13.6) = 12.09 (eV) When this 3à 1 atomic transition occurs, this energy is released in the form of electromagnetic energy. These results DO DEPEND ON THE TYPE OF ATOM OR MOLECULE 1 2 3 4 5 PDF 文件使用 "pdfFactory" 试用版本创建 www.fineprint.cn
Some Other Quantum Transitions Initial Final Energy diff. Energy diff. Wavelength Region State State [eV] [ [nm] 2 1 10.2 1.6x1018 121 X-ray 3 1 12.1 1.9x1018 102 X-ray 4 1 12.8 2.0x10-18 97 X-ray 3 2 1.89 3.0x10-19 654 Red 4 2 2.55 4.1x10-19 485 Aqua 5 2 2.86 4.6x1019 432 Violet 400 450 500 550 600 650 700 750 (ultra)Violet Blue Cyan Green Yellow Orange Red (infra) PDF文件使用"pdfFactory”试用版本创建www.fineprint.cn
Some Other Quantum Transitions Initial State Final State Energy diff. [eV] Energy diff. [J] Wavelength [nm] Region 2 1 10.2 1.6x10-18 121 X-ray 3 1 12.1 1.9x10-18 102 X-ray 4 1 12.8 2.0x10-18 97 X-ray 3 2 1.89 3.0x10-19 654 Red 4 2 2.55 4.1x10-19 485 Aqua 5 2 2.86 4.6x10-19 432 Violet PDF 文件使用 "pdfFactory" 试用版本创建 www.fineprint.cn
Cosmic rays Cosmic Rays are energetic particles that impinge on our atmosphere. Primary Cosmlc Rays They come from all directions. When these high energy particles strike atoms/molecules in our atmosphere,they produce a spray of particles. Many“exotic”particles can be created.As long as they are not so massive as to violate energy conservation. Some of these particles are unstable and“decay”quickly into other stable particles. Any of these exotic particles can reach the surface of the earth. PDF文件使用"pdfFactory”试用版本创建ww.fineprint.cn
Cosmic Rays q Cosmic Rays are energetic particles that impinge on our atmosphere. q They come from all directions. qWhen these high energy particles strike atoms/molecules in our atmosphere, they produce a spray of particles. q Many “exotic” particles can be created.As long as they are not so massive as to violate energy conservation. q Some of these particles are unstable and “decay” quickly into other stable particles. q Any of these exotic particles can reach the surface of the earth. PDF 文件使用 "pdfFactory" 试用版本创建 ÿwww.fineprint.cn
Discoveries in Cosmic Rays >1932 Discovery of the antiparticle of the electron, the positron.Confirmed the existence and prediction that anti-matter does exist!!! >1937:Discovery of the muon. It's very much like a "heavy electron'”. >1947:Discovery of the pion We'll touch on these today...and some other things... PDF文件使用"pdfFactory”试用版本创建ww.fineprint.cn
Discoveries in Cosmic Rays Ø 1932 : Discovery of the antiparticle of the electron, the positron. Confirmed the existence and prediction that anti-matter does exist!!! Ø 1937 : Discovery of the muon. It’s very much like a “heavy electron” . Ø 1947 : Discovery of the pion. We’ll touch on these today… and some other things… PDF 文件使用 "pdfFactory" 试用版本创建 ÿwww.fineprint.cn
Dirac In 1929 Paul Dirac managed to combine quantum mechanics and special relativity The energy of a particle can be given by: E2=m,2c4+p2c2 But this equation leaves both a positive and a negative solution E=±Vm,2c4+p2c2 PDF文件使用"pdfFactory”试用版本创建www.fineprint.cn
Dirac • In 1929 Paul Dirac managed to combine quantum mechanics and special relativity The energy of a particle can be given by: • But this equation leaves both a positive and a negative solution 2 2 4 2 2 E m c p c = o + 2 4 2 2 E m c p c = ± o + PDF 文件使用 "pdfFactory" 试用版本创建 www.fineprint.cn