CHEM-220- Inorganic Chemistry
BOOKLET QUESTIONS AND ANSWERS
Exercise 1.1a
Identify whether the element is in the s,p,d or f block of the periodic table, and whether the
element is a metal or non-metal.
i. Na = s, metal
ii. F = p, non-metal
iii. Ni = d, metal (transition)
iv. Eu = f, metal (transition)
v. Ca =s, metal
vi. Ga = p, metal (transition)
vii. Pb = p, metal (transition)
viii. Bi = p, metal (transition)
Exercise 1.1b
Complete the following table with the missing values.
Element
Protons
Neutrons
Electrons
Mass
Number
Atomic
Number
Nuclear
symbol
Iridium
77
115
76
192
77
192Ir+
Uranium
92
146
92
238
92
238U
Selenium
34
44
36
78
34
78Se2-
Gold
79
118
78
197
79
197Au+
Osmium
76
115
76
191
76
191Os
Europium
63
89
60
152
63
152Eu3+
Exercise 1.1c
i. If an element consists of 37.50% atoms with a mass of 184.9650u and 62.50% atoms with a
mass of 186.9560u, what is the atomic mass of the element?
0.3750 x 184.9530=69.357
0.6250 x 186.9560 = 116.8475
69.357 + 116.8475 = 186.2045u
ii. The element strontium exists as four isotopes with the following fractional abundances and
atomic masses. Calculate the average atomic mass of strontium:
84Sr 83.913u x 0.56% = 0.4699
86Sr 85.909u x 9.86% = 8.4706 87.616u
87Sr 86.909u x 7.00% = 6.0836
88Sr 87.906u x 82.58% = 72.592
