Bài 12. Liên kết ion - Tinh thể ion

VÝ dô: Sù t¹o thµnh ion Na+ tõ nguyªn tö Na
(Z=11)

+

11+

+

Na

Na+

1s22s22p63s1

1s22s22p6

1e


2+
Mg
(2,8)
Mg(2,8,2)

Al3+(2,8)
Al(2,8,3)
12+

Mg → Mg2+ + 2e

13+

Al → Al3+ + 3e


Sù h×nh thµnh anION

17+

Cl (Z=17)

Cl + 1e → Cl-

8+

O(Z=8)

O + 2e → O2-


II

Sù t¹o thµnh liªn kÕt ion

ThÝ dô 1: XÐt sù h×nh thµnh liªn kÕt ion trong
ph©n tö NaCl

+

17+

11+

Liªn kÕt ion
Na+(2,8,1)
(2, 8)
PTHH

Na+ + Cl– →
2 1e
NaCl

x
2 Na +

Cl–(2,8,7)
(2, 8, 8)
Cl

Cl2 → 2Na+Cl-

-


ThÝ dô 2: XÐt sù h×nh thµnh liªn kÕt ion trong ph©n tö
MgCl2

Cl (2,8,7)

17+

Mg(2,8,2)

Cl (2,8,7)

17+

12+

Cl- (2, 8, 8)

Mg2+ (2,8)

Cl- (2, 8, 8)

Mg 2 + + 2Cl− 
→ MgCl 2

Liªn kÕt ion lµ liªn kÕt ®îc h×nh thµnh bởi lùc hót tÜnh
®iÖn gi÷a c¸c ion mang ®iÖn tÝch tr¸i dÊu


Tæng kÕt
Nhêng e
 Nguyªn tö kim lo¹i
 Nguyªn tö phi kim
 Liªn kÕt ion. Cation
Anion

NhËn e

Cation (ion d¬ng)
Anion (ion ©m)

Hót nhau

Liªn kÕt
ion


1

56

Fe2+
Sè proton, notron, electron trong ion
26
lµ

A

26, 30, 26

C

26, 30, 28

B

24, 30, 24

D

26, 30, 24


2

2BiÕt S(Z=16), O(Z=8). Sè electron trongSO
ion
4
lµ.

A

48

C

50

B

46

D

26

3

Cation M2+ cã cÊu h×nh electron 1s22s22p6. CÊu
h×nh electron cña nguyªn tö M lµ:

A

2
2
6
2
1s
2s
2p
3s
2
2
6
1s 2s 2p 3s2

B

2
2
4
1s
1s22s
2s22p
2p4

C
D

2
2
6
2
6
2
1s
1s22s
2s22p
2p63s
3s23p
3p64s
4s2

2
2
2
1s
2s
2p
2
2
1s 2s 2p2


4

Anion X2- cã cÊu h×nh electron líp ngoµi cïng lµ
3s23p6. VÞ trÝ cña X trong b¶ng tuÇn hoµn lµ

A

Chu k× 3, nhãm
VIIIA

B

Chu
Chuk×
k×4,
4,nhãm
nhãmIIA
IIA

C

Chu
Chuk×
k×3,
3,nhãm
nhãmIVA
IVA

D

Chu

Chuk×
k×3,
3,nhãm
nhãmVIA
VIA


Bµi tËp vÒ nhµ
Bµi 3, 4, 5, 6
SGK -Trang 60