Chem 121: Homework 4
A.
isotope
symbol
1.
75
34
Se 2"
43
20
Ca 2+
!
B. a) 1s22s22p6
C.
127
53
I
number of
protons
number of
neutrons
number of
electrons
34
41
36
2.
20
3.
23
4.
18
5.
53
6.
74
7.
54
!
b) 1s22s22p63s23p64s23d104p6
c) 1s22s22p6
Br -: 1s22s22p63s23p64s23d104p6
Isoelectronic with Kr, Se2-, As3-, Rb+ and Sr2+ (the question only asked for three ions.)
D.
E.
70. You’d expect Li and Na to be most similar, as they are both in the same group (Alkali
Metals.)
76. a) +6
b) -2
c) -3
d)+2
80. a) False; it would have 26 protons and 25 electrons. b) False; it would have 54 electrons. c)
and d) are True.
86.
FBe
BrAl3+
O2-
10
4
35
10
10
Chapter 5
38.
1
3
1
1
3
1
4
12
4
1
2
2
50. Al2O3
52. Ca(OH)2
BeI2
CaCO3
CaS
Ca3(PO4)2
54. a) RbNO3
b) Sr(NO3)2
c) In(NO3)3
Rb2SO4
SrSO4
In2(SO4)3
Rb3PO4
Sr3(PO4)2
InPO4
CaI2
CaHPO4
56. lithium iodide; magnesium sulfide; barium fluoride; sodium fluoride
58. mercury (II) bromide;
62.
a) barium hydroxide
d) lead (II) sulfate
66. CuClO3
KMnO4
iron (III) oxide;
copper (II) iodide;
b) iron (III) hydroxide
e) potassium hypochlorite
PbCrO4
CaF2
tin (IV) chloride
c) copper(I) nitrite
f) magnesium acetate
Fe3(PO4)2
LiHSO4