Ch. 3 & 4  atom & molecules  test     [35 points]                   honors Chem

 

For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.                  Clearly identify the problems done and do them in sequence and your answer must begin and end on the same page of paper; otherwise, you may lose points.

 

 

Academic Honesty:   The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus.  I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam.  If you violate any of the preceding items or do not sign, your semester grade is a F.

 

                                                                                                Signature:  ___________________

 

1.  fill-in the below table  [15 points]

 

symbol

# protons

# neutrons

# electrons

charge

Atomic mass

 

90Sr2+

 

 

38

 

52

 

36

 

+ 2

 

90

 

60 Ni+3

 

 

28

 

32

 

25

 

+ 3

 

 60

 

210 Bi-3

 

 

83

 

127

 

86

 

- 3

 

210

 

 

2.  fill-in the below table; compounds might be hypothetical.  [10 points]

 

Chemical formula

Chemical name

 

K2CO3

 

potassium carbonate

 

 

CuO

 

copper (II) oxide

 

 

P3Br7

 

triphosphours heptabromide

 

 

S2Cl5

 

disulfur pentachloride

 

 

Hg2 S

 

Mercury (I) sulfide

 

 

3.  Based on the following hypothetical information

 

isotope

Abundance

 

54Mn

 

 

70 %

 

55Mn

 

 

20 %

 

57Mn

 

 

10 %

 

determine the average atomic mass of Mn;  show your work, including any relevant formula / equation and the proper units in your work / answer.  [10 points]

 

54.5 amu