Physics 2 - Lecture 9: Atomic Physicss - Huynh Quang Linh

Nội dung text: Physics 2 - Lecture 9: Atomic Physicss - Huynh Quang Linh

1. ATOMIC PHYSICS Tran Thi Ngoc Dung – Huynh Quang Linh – Physics A2 HCMUT 2016
2. THE SCHRÖDINGER EQUATION IN THREE DIMENSIONS 2m  (E U) 0 2 2 E  U  2m Potential KineticEnergy Energy ANS : (ii) must be negative
3. Energy – level diagram for a particle in a 3 dimensional cubic box Having two or more distinct quantum states with the same energy is called degeneracy, and states with the same energy are said to be degenerate
4. Wave function of electron The wave function describing the state of the electron depends on 3 quantum numbers n, ℓ ,m  (r) (r,, ) Rn, (r)Y,m(, ) n = 1, 2, 3, . Principal quantum number ℓ = 0,1, 2 , n-1 Orbital quantum number m = 0, 1, 2,  3, , ℓ Magnetic quantum number Rnℓ(r): Laguerre Yℓm(,): Spherical functions harmonics Zr 1 3 / 2 Z Y0,0 R 2 e a o 4 1,0 a o 3 i 3 i 3 / 2 Zr Y1,1 sine ;Y1, 1 sine 1 Z Zr 8 8 R 2 e 2a o 2,0 a a 3 8 o o Y1,0 cos Zr 8 3 / 2 1 Z Zr 2 2a o 4   R 2,1 e a o 0.53 10 10 m 24 a a o 2 o o mee
5. ENERGY OF ELECTRON IN HYDROGEN ATOM Energy of the electron in the Hydrogen atom is 1 m e4 13.6(eV) E e n 2 2 2 2 n 2(4 o )  n Conclusions 1. Energy of the electron in the Hydrogen atom is quantized and E<0. 2. n increases, the distance between 2 adjacent energy levels decreases. 3. The Ionization energy of hydrogen atom is the energy required to remove the electron from the atom. This is the energy supplied so that the electron can move from E1 to E 13.6eV E E E1 0 ( ) 13.6eV 12
6. 3. For a given n, there are n values of ℓ, for a given value of ℓ , there are 2ℓ +1 values of m 2, For a given n, the number of states that have the enegy En is n  n 1 n(n 1) (2 1) 2(1 2 (n 1)) n 2 n n2  0 2 n 2,E2 3.4(eV) n 2,  0; m 0 2,0,0  1; m 0, 1 2,1,0,2,1,1,2,1, 1, The degeneracy of the energy level E2 is 4. There are 4 states having the same E2.
7. n = n = 6 Light of the maximum n = 5 frequency of the Paschen Pfund series = light of minimum n = 4 wavelength of the Paschen series Bracket n=3 max E E3 0 ( 1.5) Paschen 1.24 1.24 min 0.82m max 1.51(eV) n=2 Balmer max, min of Lyman series n=1 Lyman min, max of Lyman series
8. ENERGY OF VALENce ELECTRON IN ALKALI METAL ATOM Energy levels depend on the 13.6(eV) E quantum numbers n and ℓ n, 2 (n  ) Energy of valence electron can be written as nX Selection rules ℓ 0 1 2 3  1 s p d f ℓ : quantum defect, depends on the orbital quantum nX nS nP nD nF number  and on the atom.  1 Atom s p d f Li 0.412 0.041 0.002 0,000 Na 1.373 0.883 0.010 0.001
9. SPECTRAL LINES of ALKALI METAL ATOMS