Chapter-8 - CHAPTER 8 ELECTRONIC STRUCTURE OF ATOMS light...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
1 CHAPTER 8 ELECTRONIC STRUCTURE OF ATOMS • light, photons, photochemical reactions • atomic spectra • quantum mechanics, atomic orbitals • electron configurations
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Light and photons radiation - matter interactions atomic/molecular structural information wavelength- dependent UV,VIS, IR absorption/emission spectroscopy properties of chemical bonds, electrons X-ray diffraction structure of matter
Background image of page 2
3 Maxwell (1864) light = electromagnetic wave (oscillating electric + magnetic fields) E H v wavelength (m) frequency (s -1 ) velocity v (m s -1 ) (v =    ) amplitude A (J) Fig. 8-2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 electromagnetic spectrum 1 nanometer (nm) = 10 -9 m 1 Ångström (Å) = 10 -10 m
Background image of page 4
5 dual nature of light Planck (1900) radiation energy is quantized energy quantum E = h h = 6.626 10 -34 J.s Einstein (1905) light is a stream of photons (massless energy quanta) wave (v, , ) and/or photons (E = h = hc/ )
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 photoelectric effect observations: - min for a given metal - E k (e-) as   - current as light intensity Einstein’s explanation: 1 photon extracts 1 e- h (photon) = E i (metal) + E k (e-) = h min + E k (e-) E k (e-) = h - h min E k (e-) > 0 only if > min e-’s ejected from metal
Background image of page 6
7 photochemical reactions H 2 (g) + Cl 2 (g) 2 HCl(g) light Cl 2 + h   2 Cl• (initiation) 2 Cl• + 2 H 2 2 HCl + 2 H• 2 H• + 2 Cl 2 2 HCl + 2 Cl• 2 Cl• + 2 H 2 2 HCl + 2 H• etc. .. exothermic chain reaction Cl 2 2 Cl• H = + 243 kJ/mol photon energy h = hc/ 243 10 3 /6.02 10 23 J photon wavelength   492 nm (green)
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 reactions in upper atmosphere O 2 + h   2 O* for < 242 nm O 2 + O + N 2 O 3 + N 2 * ozone O 3 O 2 + O* h 280-315 nm (UV B) ozone layer = UVB filter
Background image of page 8
9 Atomic spectra emission/absorption of light by atoms depends on their electronic structure Na vapour street lamps: Na Na* low E high E voltage relaxation by emission of light
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10 emission lines helium emission spectrum Fig. 8-9
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/17/2011 for the course ENGINEERIN chem 1e03 taught by Professor Aaa during the Spring '11 term at McMaster University.

Page1 / 47

Chapter-8 - CHAPTER 8 ELECTRONIC STRUCTURE OF ATOMS light...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online