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Properties of Matter: Investigation 2 –










By observing a sample of matter and measuring its chemical and physical properties, we gradually acquire enough information to characterize it and distinguish it from other kinds of matter. This is the first step in the development of chemical science, in which interest is focused on specific types of matter.


Chemists may develop a synthetic fiber that can stop a speeding bullet or figure out how to make hair-styling gel work better.


Answer the following Focus Questions: 

  • Can you tell the difference between an element and a compound by calculating density and observing chemical reactions? 
  • Can you determine the identity of an unknown substance by calculating its density and observing chemical reactions? 



Read the Background(s) in the Investigation in your SDR. When you have finished, consider the following concepts as a class:

  • Density is a property of matter that defines how much matter exists in a particular space.
  • The density of matter depends on two things, mass and volume.
  • Density can be calculated by using the formula: Density = Mass ÷ Volume.
  • Chemical reactivity is a property of elements and compounds.
  • A chemical reaction can occur when an element or compound is combined with another element or compound.
  • Two signs of a chemical reaction are a change in color or formation of a gas (bubbles).


The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • density


  • You will continue to investigate the six unknown samples. As a part of your investigation, you will explore another physical property of matter, density, and some chemical properties of matter.
  • Complete the Recall section in your SDR.
  • Review the difference between physical and chemical properties, stressing the change in chemical composition during a chemical change, and the simple change in form during physical changes.
  • In the next part of your investigation, you will see whether chemical reactions can show you if two physically different samples are actually the same substance.
  • Think of what you already know about changes. 
    • How are physical changes and chemical changes different? 
    • Can you think of an example of a physical change? 
    • Can you think of an example of a chemical change?
  • Play the video below. Remember to follow along with your SDR and make any notes that you think might be helpful.
  • After the video, divide into your lab groups to discuss your strategy for the lab. For example, you may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video below is to allow you to anticipate the laboratory experience you will soon encounter. You should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.


Review the Investigation procedures and watch the video above in preparation for the Lab.