ch. 3 & 4  atoms  & molecules   test   [30 points]                 honors Chemistry

 

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:  ___________________

 

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. 

 

 

1.  fill-in the table.  [10 points]

 

symbol

# protons

# neutrons

# electrons

charge

Atomic mass

65Cu2+

 

 

 

 

 

 

47

 

 

+ 1

110

 

 

2.  fill-in the table  [10 points]

 

Chemical formula

Chemical name

Sodium carbonate

 

 

(NH4)2S

 

Sn3(PO4)4

 

P3Br7

Tetra-silicon nona-iodide

 

 

 

3.  what is the average atomic mass of nitrogen if the % abundance of:  14N = 85%; 15N = = 10%; 17N = ?  [10 points]