Week 3: Describing Matter

We have learned that there are several ways to describe matter. Some of those ways include the state of matter and identifying matter by specific properties.  The properties can either be physical or chemical.  Physical properties include color, shape, magnetism, density, malleability, boiling point, and phase at room temperature.  Chemical properties include the matter's ability to form gas bubbles, rust, react with other substances, not react with other substances, and ability to burn. Keep in mind that chemical properties are properties that we can potentially witness when we try to make a new substance.  In other words, they are not readily seen.  For example, we know the car is made of metal. We also know that the metal has the ability to rust over time when exposed to the right elements, but it is not something we will immediately see on the metal.  

Now let's look at how matter can change. Just like there are physical and chemical properties, they're also physical and chemical changes.  Physical changes do not change the chemical make up of matter.  They just change the appearance.  So if I have a paper and rip that paper in half, it is still just paper. Physical changes are reversible for the most part.

Chemical changes mean that a chemical reaction has occurred between substances resulting in a newly formed substance.  Remember the example of sodium (Na) and chlorine (Cl)? Separately, Na is a soft, silvery metal and Cl is a yellow-greenish gas. Once combined they create sodium chloride (NaCl), which is commonly known as table salt. Chemical changes are irreversible. 

Check out Mr. Kent's Chemistry Page for more information on this topic.

Here is cartoon video from my Youtube channel on this topic.