spectroscopy. the spectral colors correspond to different wavelengths of electromagnetic radiation
TRANSCRIPT
![Page 1: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/1.jpg)
Spectroscopy
![Page 2: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/2.jpg)
The spectral colors correspond to different wavelengths of electromagnetic radiation
![Page 3: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/3.jpg)
Is Light a Wave or a Particle?
Argument: Light is reflected according to the law of reflection, which is a property of waves. Therefore light is a wave.
![Page 4: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/4.jpg)
Counterargument
![Page 5: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/5.jpg)
px = mvx = m v sin(), py = mvy = m v cos()
![Page 6: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/6.jpg)
Fx = m dvx/dt, Fy = m dvy/dt
![Page 7: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/7.jpg)
Fx = 0 => vx is unchanged
Perfectly elastic collision =>
½ m (vx2 + vy
2) is unchanged
![Page 8: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/8.jpg)
Fx = 0 => vx is unchanged
Perfectly elastic collision =>
½ m (vx2 + vy
2) is unchanged
Therefore vy (after) = - vy (before)
![Page 9: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/9.jpg)
![Page 10: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/10.jpg)
We cannot deduce, simply from the law of reflection, whether light is a wave or a particle.
![Page 11: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/11.jpg)
We cannot deduce, simply from the law of reflection, whether light is a wave or a particle.
There is a long history of controversy in optics over whether light is a wave or a particle.
![Page 12: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/12.jpg)
There is excellent evidence that light is emitted and absorbed from matter is discrete amounts, very much like particles.
Each “particle” of light carries an energy E. If the light has frequency f, the “particle” has energy
E = hf where h = 6.626 x 10-34 J s = 4.136 x 10-15 eV s h is called Planck’s constant and the
“particle” of light is called a photon.
![Page 13: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/13.jpg)
![Page 14: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/14.jpg)
classical physics: A mechanical system has states of motion at a continuous range of energies.
E m v k x 12
2 12
2
![Page 15: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/15.jpg)
Quantum Physics
Atoms and molecules have states of excitation separated by discrete energies
![Page 16: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/16.jpg)
![Page 17: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/17.jpg)
![Page 18: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/18.jpg)
E = 12.087 eV – 10.199 eV = 1.888 eV
The emitted photon has an energy of 1.888 eV
f = E/h = 1.888 eV/ (4.136 x 10-15 eV s)
= 4.565 x 1014 Hz
= c / f = (3 x 108 m/s) / (4.565 x 1014 s-1)
= 6.57 x 10-7 m = 657 nm
![Page 19: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/19.jpg)
E = 12.087 eV – 10.199 eV = 1.888 eV
The emitted photon has an energy of 1.888 eV
f = E/h = 1.888 eV/ (4.136 x 10-15 eV s)
= 4.565 x 1014 Hz
= c / f = (3 x 108 m/s) / (4.565 x 1014 s-1)
= 6.57 x 10-7 m = 657 nm
The atom emits red light in this transition
![Page 20: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/20.jpg)
![Page 21: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/21.jpg)
![Page 22: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/22.jpg)
![Page 23: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/23.jpg)
![Page 24: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/24.jpg)
![Page 25: Spectroscopy. The spectral colors correspond to different wavelengths of electromagnetic radiation](https://reader035.vdocuments.mx/reader035/viewer/2022070413/5697bff01a28abf838cbaae7/html5/thumbnails/25.jpg)
E1 = 12.087 eV – 10.199 eV = 1.888 eV
f1 = E/h = 1.888 eV/ (4.136 x 10-15 eV s)
= 4.565 x 1014 Hz
1= c / f = (3 x 108 m/s) / (4.565 x 1014 s-1)
= 6.57 x 10-7 m = 657 nm
E2 = 2.549 eV, E3 = 2.855 eV
2 = c / f2 = hc / E2 = (1240 eV nm)/ 2.549 eV
= 486 nm
3 = c / f3 = hc / E3 = (1240 eV nm)/ 2.855eV
= 434 nm