Describing Matter Chapter 2 Section 1

What is Matter? What is a Substance?

Properties of Matter Substance: Single kind of pure matter with a specific makeup and set of properties. 1. Physical Property: Characteristic of a pure substance that can be OBSERVED without changing it into another substance. Helps you identify/classify/describe matter ie: Density, hardness, texture & color

What are some Physical Properties?

2. Chemical Properties Characteristic of a pure substance that describes its ability to change into different substances because of its composition. CAN’T be observed by looking or touching ie: a. IRON reacts with oxygen to form RUST… a completely different/new substance. b. SILVER reacts with sulfur in the air to form TARNISH.

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

BRAIN BREAK! Stand up, stretch your arms, turn to your partner, and tell him/her what a Substance is. Then, let him/her tell you the Difference between Physical and Chemical Properties. Then, stretch your arms again and take your seat.

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 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

Mixtures 1. Heterogenous Mixture= You can see the different parts Made of two or more substances “Mixed together” but NOT Chemically Combined Each substance in the mixture retains original properties 1. Heterogenous Mixture= You can see the different parts 2. Homogenous Mixture= So evenly mixed that you can’t see the different parts a. Solution = Type of Homogenous Mixture

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