13th edition

Chapter 4: Properties of Matter:
11th & 12th Editions, p65-70

13th Edition, p61-66

14th Edition, p62-68

Read the sections on Properties of Matter, Physical Changes, and Chemical Changes.

Remember the tutorial on Classifying: Calming the Chaos? That's where I talked about humans having a desire to classify things so it's more understandable. The Periodic Table of the Elements classified elements. Now we are classifying the properties that elements and compounds have. The general classification is with their physical properties (properties they have on their own) and chemical properties (properties of how they react with other chemicals)..

11th & 12 Editions, p67. 13th Edition, p63. 14th Edition, p64.  The textbook makes an important statement about substances (element or compounds). It says:

"No two substances have identical physical and chemical properties."

This simple statement has valuable consequences. For example, these coins and nuggets are all made of gold. If someone tries to use some other substance in place of gold, then it will not have all the same physical and chemical properties of gold. It might look like gold and be heavy but it will not have all the properties of gold.

In the old days, when people used gold coins, they would test a suspicious coin by biting it. One of gold's physical properties was that it was softer than most metals. Also, the density (a physical property) of gold was higher than other metals, so that was another way to test it. A drop of strong acid would have no affect on gold (chemical property) but does on other metals. In other words, there are no other metals or alloys of metals that can have the same physical and chemical properties of gold. So a person who checks the suspicious gold against the physical and chemical properties of gold is guaranteed to find out if it's gold or not.

Read the above sections in the textbook and then take the quiz called "Quiz: Physical and Chemical Properties" at the Sapling Learning website.