Describing Matter Chapter 2 Section 1 Structure of Matter Students know that compounds are formed by combining two or more different elements and that compounds have properties that are different from their constituent elements.

Properties of Matter Matter Anything that has mass and takes up space Substance Single kind of pure matter with a specific makeup and set of properties. cannot be separated by physical or mechanical means it has uniform composition its properties are constant Physical Property Characteristic of a pure substance that can be observed without changing it into another substance. Helps you identify/classify/describe matter ex: density, hardness, texture & color

What is Matter? What is a Substance?

Chemical Properties Chemical Properties Characteristic of a pure substance that describes its ability to change into different substances because of its composition Cannot be observed by looking or touching Examples a. Iron reacts with oxygen to form rust . . . a completely different/new substance. b. Silver reacts with sulfur in air to form tarnish . . . again, a new substance!

What was the substance before and what did it become? Burning produces new products… heat, gas, and ashes

Elements Element The simplest substance A substance that cannot be broken down into any other substance by chemical or physical means. Can be identified by its specific physical and chemical properties. Atoms Basic particle of all elements Different elements are made of different atoms. Chemical Bond When atoms combine, they form molecules

Compounds

Compounds A pure substance made of two or more elements chemically combined in a set ratio Can be represented by a Chemical Formula When elements combine to form compounds, they have properties that are different from those of the uncombined elements. For example: Carbon Dioxide = CO2 Glucose = C6H12O6

Snail Shell is composed of Calcium Carbonate = Calcium, Carbon and Oxygen

Common Compounds

Mixtures Made of two or more substances “Mixed together” but NOT chemically combined Each substance in the mixture retains original properties Homogenous Mixture = Evenly mixed, you can’t see the different parts (Solution = Type of Homogenous Mixture) Heterogeneous Mixture = You can see the different parts

Heterogeneous = Not uniform composition Parts can be separated Homogenous = Uniform composition Parts cannot be separated

Test Your Knowledge