Name:  _______________________________                                  date:  _______________                     period:  _____

Ch. 3 & 4  atoms & molecules                                           40 points                                              honors chem

  1. fill-in the below table.  [5 points]

Chemical formula

Chemical name

PbCl4

 

 

Rubidium sulfate

 

Potassium bicarbonate

 

Triphosphorus pentaoxide

S2Br6

 

2.  fill-in the below table.  [13 points]

symbol

# protons

# neutrons

# electrons

charge

Atomic mass

 

25

 

 

+ 2

56

 

 

142

86

 

230

34S -2

 

 

 

 

 

3.  Based on the following hypothetical (?) information in regards to the abundance of arsenic isotopes,

76As     5.0%
75As     80.0 %
74As     15.0%

what is the average atomic mass of arsenic ?  show your work,, including any equation / formula and the appropriate units in your answer.  [6 points]

4.  In regards to the following chemical formulas, identify the atoms, by their chemical name, and the number of that atom in one molecule.  [16 points]

  1.  Ba(C2H3O2)2:
  1.  (NH4)2SO4: