1. Describing Matter

2. Properties of Matter  Matter is anything that has mass and takes up space.  Matter can be hard, soft, rough or smooth, round, square, hot or cold.  It can be small enough to fit in your pocket or as large as the Earth.

3. States of Matter  There are three states of matter: 1. Solid (Ice) 2. Liquid (Water) 3. Gas (Water Vapor) o https://www.youtube.com/watch?v=cBBm dqti_Kg

4. Characteristic Properties  Some properties of matter, such as size or amount, are true only for a given sample of matter.  For example, a piece of ice can be as small as an ice cube or as large as a glacier. The substance is still ice.  Some properties are true for a particular kind of substance no matter what the sample size. These properties are called characteristic properties. (For example, all diamonds have the same hardness.  Since characteristic properties for a given substance never change, they can be used to identify unknown matter.

5. Boiling Point  The temperature at which a liquid boils is called its boiling point.  Boiling point is an example of a characteristic property of a substance.  Boiling points can be an excellent way to tell one liquid from another.  https://www.youtube.com/watch?v=nVr9 WdPjJ-s

6. Melting Point  The temperature at which a solid melts is called its melting point.  Because a solid substance melts at one temperature only, melting point is another characteristic property.

7. Checkpoint  What are two examples of characteristic properties? 1. Boiling Point 2. Melting Point

8. Changes in Matter  Changes in the state of matter, such as boiling or melting are examples of physical changes.  There are two types of changes in matter: 1. Physical changes 2. Chemical changes

9. Physical Changes  Physical changes change the form of a substance, but does not change what the substance is. (The pop can is still a pop can, just crushed and the ice is water even when its solid.

10. Chemical Changes  In chemical changes, one or more substances combine or break apart to form new substances. (Heating sugar and turning into caramel)  When the process is complete, the original sugar particle no longer exists

11.  The ability of a substance to undergo a specific chemical change is another example of a characteristic property.  This property is called the chemical activity of the substance.

12. Types of Matter  Matter can be classified into two general categories: 1. Mixtures 2. Pure Substances (elements and compounds)

13. Mixtures  A mixture consists of two or more substances that are mixed together but not chemically combined.  In a mixture the individual substances keep their separate properties.

14.  Scientists often classify mixtures by how well they are mixed together.  In mixtures like ocean water (salt water) the parts have been blended so well together that they appear to be a single substance.  This type of mixture is called a solution.

15. Pure Substances  A pure substance is made of only one kind of matter and has definite properties.  Examples of pure substances are sugar, salt, iron, aluminum and copper.  Every piece of a pure substance is always the same no matter what the form.

16. Elements  Some pure substances called elements cannot be broken down into other substances by any chemical means.  Individually or in combination, the elements form every object in the world!

17. Compounds  Elements combine in different ways to form a huge variety of compounds.  A compound is a pure substance formed from chemical combinations of two or more different elements.  An example of a compound is water.  Just as symbols are used to represent elements, formulas are used to represent compounds.

18. Compound Formulas

19.  The properties of compounds are always different from the properties of the elements that formed them.

20. REVIEW  Using the information you just gathered, answer the following questions: 1. List the three principal states of matter and give two examples of each 2. What is the difference between a physical change and a chemical change? 3. What is meant by a characteristic property of a substance?