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第 七 章 原子结构和. Chapter 1 Atomic Structure. 本章教学要求. 1. 了解电子的运动特性:物理量量子化、波粒二象性。. 2. 了解测不准原理的意义和波粒二象性的统计解释。. 3. 粗知波函数、量子数的物理意义,掌握量子数的取值规则。. 4. 粗知原子轨道图形表示和电子云图,了解径向分布图的意义。. 5. 了解单电子原子内轨道能级和简并轨道的概念。. 6 . 了解有效电荷的概念,粗知屏蔽作用和钻穿效应对轨道能级的影响,了解不相容原理、能力最低原理和洪特规则,掌握原子排布电子规律,了解能级组概念。.

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第 七 章 原子结构和

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7006915

Chapter 1

Atomic Structure


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1

2

3

4

5

6

7


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7.1 (wave-particle dualitya fundamen-tal concept of quantum mechanics)

7.1.1 an emba-

rrassment of the concepts of the classical

physics)

7.1.2 particle like wave)

7.1.3 wave like particle)


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7.1.1

Rutherfords experiment on particle bombardment of metal foil

Rutherford

- .

1. (nucleus)

2.

3.

4. .


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isthe embarrassment of the concepts of

the classical physics ?

What

An unsatisfactory atomic model

, , . 4, , , .

, , , . , .


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The electromagnetic spectrum

.

7.1.2

. .

.


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.

)

h

(

h

)

(

,

h

.

,

h

,

.

,

h

,

.

1900, (Plank M) (E)(), E = h

h(Planck constant), 6.62610-34 Js.

Plank

, h(1, 2, 3), 0.5, 1.6, 2.3..

, ().


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The photoelectric effect

1905, (Einstein A)(photoelectric effect), . ,. (), , .

, , 1(photons), . , , .

. (quantummechanics).


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The experiments of

particle of electrons

The Planck

equation

The photoelectric effect

Plank

Einstein

quantum mechanics.


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7.1.3

1924Louis de Broglie m ,v ,

.1924

.

h Planck

.


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X

K

M

D

V

(a)

(b)

P

1927Davissson Germer Ni .

Schematic drawings of diffraction patterns by light, X- rays, and electrons

A1(a)(b)


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Question 2

m = 1.0 10-2kg, = 1.0 103m s-1,

= 6.6 10-35 m

  • .. x.


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7.2

(thequantum mechanical model of the structure

of hydrogen atom Bohr model)

, , ., . .

:

.


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The allowed values for n in above equation

n1

n2

Name

2,3,4,

3,4,5,

4,5,6,

5,6,7,

6,7,8,

1

2

3

4

5

Lyman series

Balmer series

Paschen series

Brackett series

Pfund series

, (Lyman), (Balmer), (Paschen)(Brackett)(Pfund). (wave number):

, , cm-1; R, 1.097 37105cm-1; n2n1, . n

Balmer

n = 3 H

n = 4 H

n = 5 H

n = 6 H


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..

Bohr

Bohr.


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Bohr

(Bohr N)19133

. , . , , Lh/(2)

m v , r , h , n (quantum number), 1,2,3,. , , , n1,2,3,4,5,6,7. n = 1 53 pm, .


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.. , .

(stationary state)

.,.

(ground state):

n 1 .. .

(excited states):

. n

. .


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.

, (E2)(E1), (, ), . ,

E = E2E1 = h

E1E2, .

E:

h: Planck


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Wave type Ha Hb Hg Hd

Calculated value/nm 656.2 486.1 434.0 410.1

Experimental value/nm 656.3 486.1 434.1 410.2

H He+Li2+B3+


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7.3 the wave

mechanical model of the structure of atom

7.3.1

(uncertainty principle and orbital in quantum

mechanical model )

7.3.2

(four quantum mummers used in defining the

movement state of electrons )

7.3.3

(Schrodinger equation and wave function )

7.3.4

(portrayal of wave function )


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Heisenberg W

Schrodinger E

, 1920(Heisenberg W)(Schrodinger E). (), , .


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7.3.1

Heisenberg uncertainty principle

, , .

, , ;, .

x p h/(4)

Rutherford Bohr

.

. , , . .


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7.3.2

, . , .

1n (principal quantum number)

n

n

..

K L M N O..


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The allowed values for angular momentum quantum number, l

n

l

1

2

3

4

(subshell symbol

0

0

0

0

s

d

1

1

1

p

2

2

d

3

f )

s

p

2 l (angular momentum quantum umber)

, lE

l 0123n-1(

s, p, d, f...

l


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The allowed values for magnetic quantum number, m

m

number of orbital

L

0(s)

1(p)

2(d)

3(f)

0

1 0 1

2 1 0 1 2

3 2 1 0 1 2 3

1

3

5

7

3 m ( magnetic quantum number)

m 01, 2l

m


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s(l = 0, m = 0 ) :

m , , s.

p(l= 1, m = +1, 0, -1)

m , , () p.


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d (l = 2, m = +2, +1, 0, -1, -2) :

m , , () d .


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f!

f ( l = 3, m = +3, +2, +1, 0, -1, -2, -3 ) :

m , , () f.


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Silver atomic ray

Small clearance space

kiln

Magnetic field

screen

Electron spin visualized

4 ms (spin quantum number)

ms +1/2-1/2

:

(+1/2)(-1/2)

, .


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0 1 2 3

Orbitalspdf

: n =2, l =0, m =0, 2s

n =3, l =1, m =0, 3pz

n =3, l =2, m =0, 3dz2

n, l, m,

n

l

m

ms

1Ei)


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Question 4

n = 4, l = 2, m = 0 .

n, l, m . l = 2 d . n = 4, 4d. m = 0, , m = 0 4d 5 4d .

Representations of the five d orbitals


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Question 5

Electron probability for a 2s orbital

.

2s(a)(r = 0), , . , , . (b). , , .

p, , . px yz , py pz xz xy .

Representatios of the three 2p orbitals


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7.3.3

Schrdinger

m,;

, E;

, (n, l, m)

(r,,)n, l, m (r,,) ;

n, l, m (r,,) , ;

, ,

.(Wave functions),

n, l, m .

= =

: .


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( x, y, z) (r,,)

r : ,

: , z r

.

: , rxyxz

.


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R(r)

7.3.4

Schrdinger

yn, l, m( r, q, f ) =

Rn, l(r)

Y l,m( q, f )

(1s, 2s, 3s)

?

r, , r . , 1s R(r) = 2e-r

:

, s R.

.


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( 2px)

, ;

(),

;

,, x

.


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(r,,)2(r,,)

, . orbit, .

;

, ; ,

(2 );

2. ,

(2 ).

orbital, . (electron clouds), . , , ., , .


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[ 2(r,,) = R 2 (r) Y 2 (,) ]

:

()

: R2

,

().

(

)


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[ 2(r,,) = R 2 (r) Y 2 (,) ]

:

()

: 4r 2 R 2

4r2R24r 2R 2

.

r=53 pm ,

53 pm

.

.


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.

, +-.

s, p, d,

s, p, d.

:

R (r)R 2 (r).

Y(,)Y 2 (,).

4r 2 R 2 (r). , 4r 2 R 2, .


7 4 the energy level of many electron atoms

7.4 (the energy level of many-electron atoms)

Pauling,L.C.(1901-1994)

7.4.1 portrayal ofPauling

approximation energy level )

7.4.2 Cotton

energy level portray )

7.4.3 ( shielding

and penetration)


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7.4.1

n , l , :E(4s) < E(4p) < E(4d) < E(4f ).

.

l , n

, : E(1s) < E(2s) < E(3s) <

E(4s )

nl

,

,

.

,

E(6s) E(4f )

E(5d).

A qualitative energy-levels diagram

for many-electron atoms


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1939, (Pauling L),

(Many-electron atoms)

, (1.13).

()

.

.,

,.

,

.

Mn(Z=25), 18

n = 1 2 9, 24s ,

53d . ,

Mn3d4s.

Mn2+ ,24s 3d


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2-

e-

e-

e-

e-

+2

+2

He

He+

He

He e 3.939 10-18 J

He+ e 8.716 10-18 J

7.4.2

1 Shielding effect

,

,

, .


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s = 0

1 s 2 s = 0.30n>1 s = 0.35

ns np(n-1) s = 0.85 (n-1)

s =1.00

nd nf s =1.00

, Z() Z* (). (shielding parameters).

Z* = Z -

Slater

1s)(2s,2p)(3s,3p)(3d)(4s,4p)(4d)(4f)(5s,5p)


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(Z*)

The effective nuclear charges of some elements in the second period

B

C

N

O

F

nuclear charges

)

Z(

5

6

7

8

9

Z*

(2

s

2.58

3.22

3.85

4.49

5.13

)

Z*

(2

p

)

2.42

3.14

3.83

4.45

5.10

2s 2p ,.

:

2s2p,

2s2p.


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2

.

: n s > n p > n d > n

, ,

E(ns) < E(np) < E(nd) < E(nf ))

,

. , 4s3

, , 3d

, .


7 5 the periodic table of elements

7.5 (The periodic table of elements)

n 1 2 3 4

K L M N

l 0 1 2 3

s p d f

2 8 18

2n2

1 3 5 7

2 6 10 14

,,

Mendeleevs periodic law(1869)

The elements if arranged according to their atomic weights, show a distinct periodicity of their properties.


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?

: (1); (2,3); (4,5);

(6,7), 7.

. , 4 n

= 4 , N .

.

, s , p

.


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IUPAC

Groups (or families):

vertical columns in the periodic table.

IUPAC, 118.

, IUPAC.

, .

IUPAC the International Union of Pure and Applied Chemistry(

.

, , .

, IUPACNomenclature of Inorganic

Chemistry. ,

Red Book .


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, .

Blocks: four areas of the periodic table, each having similar valence electron configurations.


Atomiparameters

(atomiparameters)

(atomic parameters).

7.5.1 (atomic radius)

...

(metallic radius)

(covalent radius)


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B

88

C

77

N

74

O

66

F

64

Li

157

Be

112

Na

191

Mg

160

Al

143

Si

118

P

110

S

104

Cl

99

K

235

Ca

197

Sc

164

Ti

147

V

135

Cr

129

Mn

137

Fe

126

Co

125

Ni

125

Cu

128

Zn

137

Ga

153

Ge

122

As

121

Se

104

Br

114

Rb

250

Sr

215

Y

182

Zr

160

Nb

147

Mo

140

Tc

135

Ru

134

Rh

134

Pd

137

Ag

144

Cd

152

In

167

Sn

158

Sb

141

Te

137

I

133

Cs

272

Ba

224

Lu

172

Hf

159

Ta

147

W

141

Re

137

Os

135

Ir

136

Pt

139

Au

144

Hg

155

Tl

171

Pb

175

Bi

182

Atomic radii (in pm)

Source:Wells A F,Structural Inorganic Chemistry,5th edn.Clarendon Press,Oxford(1984).


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()

,.

:,

.


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()

> >

37: [ r(Na) - r(Cl)]/6 = [191 pm - 99 pm]/6 =

15.3 pm

10: [ r(Sc) - r(Zn)]/9 = [164 pm - 137 pm]/9 =

3.0 pm

15: [ r(La) - r(Lu)]/14 = [188 pm - 173pm]/14 =

1.1 pm

:

: , (),

(Z*) . , Na(Z=11)Cl (Z=17), 6, 3s

4.56(2.517.07, 1.6).

: ,

, .

: ,

, .


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()

(Effects of the lanthanide contraction )

: ,

.

: 56Zr-Hf, Nb-Ta

.

: ,

.

6(Hf, Ta)5(Zr,

Nb), .


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7.5.2(ionization energy)

. +1, . I1I2I3, I1I2I3. , , .

E (g) == E+ (g) + e- I1

E+ (g) ==E2+ (g) + e- I2

I 1< I 2< I 3< I 4


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,

,


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Question 10

.

2Be Mg15 NP12ZnCd Hg

.


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7.5.3 (electron affinity)

, EA. , . , . , !

X(g) + e- == X- (g)

X- (g) + e- == X 2- (g)

O- (g) + e- == O2- (g) A2 = -780 kJ . mol-1

.

,.

,,.


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Question 11

?

:

;

.,

.

,

,.

, ,

.


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Question 12

1. EA(B) < EA(Al); EA(C) < EA(Si) , EA(N) <

EA(P), EA(O) < EA(S), EA(F) < EA(Cl)

2. 21.

3. 18 , 2.

  • 2 , . .

  • []ns1[]ns2. 1,

  • ns2, np. p

  • , , . , 2

  • s,

  • .

3. .


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7.5.4 (electronegativity)

.

F,; Cs(Fr)

,.

,

(electronegative);,

(electropositive).

ClO2 (Cl-O) O(3.44) Cl(3.16)

HCl Cl(3.16) H(2.20)

. Mulliken

Pauling() Allred-

Rochow.


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!

, ,

. ,

, Pauling.

!

(),()., !

,;

,.


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