STUDY GUIDE  -- 7th GRADE CHEMISTRY PROFICIENCY TEST

                                                                                    DIRECTIONS:  Study these concepts and terms. 

 

TERMS

                                    matter                                              chemical properties                   mass                                                                          

                                    volume                                             density                                       condensation                                                                                       evaporation                                      vaporization                               meniscus                                                                                              triple beam balance                         graduated cylinder  

                                    physical change                               chemical change                        phase      

                                    solid, liquid, gas, plasma                  element                                      compound         

                                    mixture                                             phase change                             molecule    

                                    atom                                                 filtration                                     chemical formula                             

                                    chemical equation                            freezing                                       boiling; boiling point                      

                                    physical properties

                                                                                     

QUESTIONS

 

• What is the density of water at 4 degrees Celsius?
• To what metric unit of liquid volume is a cubic centimeter equal?
• In order to float on water, what must a substance’s density be?
• In order to sink in water, what must a substance’s density be?
• How should one leave a triple beam balance after completing a laboratory exercise?
• Describe how one should read the volume of a liquid in a graduated cylinder.
• Describe how one should mass a powdery substance on a triple beam balance.  How should one mass a liquid?
• Name two physical means by which one can separate the parts of a heterogeneous mixture.
• How does one measure mass in the Metric System?
• What are the four general properties of matter?
• Name some specific properties of matter.
  • Describe how to use the water displacement method in order to measure the volume of a solid object in a graduated cylinder.
  • What is an element and how would you recognize it?
  • What is a compound and how would you recognize one?
  • What is the difference between a homogeneous and heterogeneous mixture?

 

 

DENSITY PROBLEMS

 

DIRECTIONS:   Be able to solve and interpret the results of the following problems             by using the        formula for density and its variations:  Density =Mass/Volume; Volume =Mass/Density;  & Mass = Density x Volume.

 

 

                             PROBLEM #1:  An object displaces 3 mL of water in a graduated cylinder.  The object’s mass is 2               grams.  What is the object’s density?  Will this object float or sink in water? Explain your answer.

 

                             PROBLEM #2:  A substances mass is 10 grams.  Its volume is 2 mL.  What is the substance’s density?  Will the substance float or sink  in water?  Explain your answer.

 

                             PROBLEM #3:  A  solid cylinder composed of a pure metal  displaces 2 mL of water.  Its mass is 21 grams.  What is the metal?  How do you know?