Week 2.docx - Written Assignment 2: Atomic Structure and...

Written Assignment 2: Atomic Structure and Chemical Compounds
Answer all assigned questions and problems, and show all work.
1. What is the mass number of an iron atom that has 28 neutrons? (3 points)
(Reference: Chang 2.13)
2. Calculate the number of neutrons of 239 Pu. (3 points)
3. Write the appropriate symbol for each of the following isotopes: (a) Z = 11, A = 23;
(b) Z = 28, A = 64 (6 points)
A ) 23 Na
11
B) 64 Ni
28
(Reference: Chang 2.17)
4. Define, with two examples, the following terms: (a) alkali metals, (b) alkaline earth
metal, (c) halogens, and (d) noble gases . (8 points)
a) Li & Na
b) Be & Mg
c) F & Cl
d) He & Ne
(Reference: Chang 2.22)
5. Identify the following as elements or compounds: (a) NH
3
, (b) N
2
, (c) CO, (d) Co,
and (e) He. (5 points)
A) Compound
B) Element
C) Compound
D) Compound
E) Element
1
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6. Give the numbers of protons and electrons in each of the following: (a) Na + , (b) Ca 2+ ,
(c) Al
3+
, (d) I
–
, (e) O
2–
, (f) N
3–
, and (g) He. (14 points)