Describing Matter Matter is anything that has mass and takes up space. Chemistry is the study of the properties of matter and how matter changes.

The properties and changes of any type of matter depend on its makeup. A substance is a single kind of matter that is pure, meaning that it always has a specific makeup. Ex. Baking soda, table sugar

Every form of matter has two kinds of properties. 1. physical properties 2. chemical properties

Physical Properties A physical property is a characteristic of a pure substance that can be observed without changing it into another substance. The physical properties of matter help you identify and classify matter in its different forms.

Examples of Physical Properties include 1.physical states of matter 2.density 3.Size 4.Luster 5.Smell 6.Texture 7.color 8.Flexibility 9.maluable

Examples of Physical Properties continued 10. Ductile 11. Conducts heat and electricity 12. Dissolving 13. hardness

Chemical Properties  A chemical property is a characteristic of a pure substance that describes its ability to change into different substances.

Examples of Chemical Properties  1. Rust forming on iron. Iron slowly combines with oxygen in the air to form a different substance called rust.  2.Ability to burn (make fire)  3.Ability to react with other substances. (ex. Vinegar and baking soda)  4. Yeast making bread dough rise. Yeast being added to bread dough which produces a gas that makes the bread rise.  5. Ability to tarnish.

Elements An element is a pure substance that cannot be broken down into any other substances by chemical or physical means. In science, we list these elements on the Periodic Table of Elements. There are over 100 elements listed on this table which can be found on pages in your textbook.

Examples of Elements Some examples of elements include Oxygen, Hydrogen, Nitrogen, Neon, Gold, Silver, Zinc, Nickel, and Helium. We will learn more about elements later on during marking period 2.

Compounds A compound is a pure substance made up of two or more elements chemically combined in a set ratio. A compound is represented by a chemical formula, which shows the elements in the compound and the ratio of the atoms.

Example of Compounds and their Chemical Formulas H2O represents water. This ratio means 2 parts Hydrogen and 1 part Oxygen.

More Examples of Chemical Formulas Carbon monoxide, a gas produced in car engines, has the formula CO; which means, 1 part Carbon to 1 part Oxygen. Carbon dioxide, a gas that we exhale from our bodies, has the formula CO 2, which means 1 part Carbon to 2 parts Oxygen.

Mixtures  A mixture is made up of two or more substances – elements, compounds, or both – that are together in the same place but are not chemically combined.

Mixtures  Each substance in a mixture keeps its individual properties. Also, the parts of a mixture are not combined in a set ratio.  Mixtures can be  Heterogeneous or  Homogeneous

Heterogeneous Mixtures In a heterogeneous mixture you can see the different parts. Examples of heterogeneous mixtures include 1. A pizza with the works (pepper, onion, sausage, pepperoni, extra cheese) 2. A fruit salad 3. Soil 4. A green salad

Homogeneous Mixtures  The substances in a homogeneous mixture are so evenly mixed that you can’t see the different parts.

Homogeneous Mixtures  Examples of homogeneous mixtures include 1. Sweet Ice tea (tea and sugar) 2. Sugar water (sugar and water) 3. Solutions 4. Air (nitrogen, oxygen, other gases) 5. Brass (copper and zinc)

Compounds vs. Mixtures A compound can be difficult to separate into its elements. But, a mixture is usually easy to separate into it components because each component keeps its own properties.

Separating Mixtures Some methods for separating mixtures include 1. Using a magnet 2. Filtering the mixture 3. Distilling a liquid solution 4. Evaporation  Pages 42 and 43 in your textbook give excellent visuals of each method.  Teacher demonstration on separating mixtures.

Knowledge Check  What is the difference between chemical and physical properties?

Answer:  Physical properties can be observed without changing pure substances into other substances. Chemical properties can be observed only be changing pure substances into other substances.

Knowledge Check  What is the difference between a heterogeneous mixture and a homogeneous mixture?

Answer:  In a heterogeneous mixture you can see the different parts. In a homogeneous mixture, the parts are evenly mixed together so you can’t see them.