What is Chemistry? What is Chemistry the Study of…..? What is Matter? Chemistry is the Study of Matter and the Changes it can undergo. What is Matter? 1. Matter is anything that has mass and volume (takes up space). 2. “Matter is anything you can put in a balloon and keep in there.” Mr.D What is most Matter made of? Generally, Matter is made of Atoms. What is Not Matter? Light Energy, Sounds, Heat (Thermal) Energy… What kinds of Changes can Matter undergo? 1. Physical Changes, 2. Chemical Changes, and 3. Nuclear Changes (on hold until Unit 3)

Physical Changes and Physical Properties What are Physical Changes? Physical Changes are changes in state or phase (solid, liquid, gas) or shape without changing the composition of matter. “Still the Same Stuff”. What are some examples of Physical Changes? Melting, freezing, boiling, condensing, cutting, molding, grinding, crushing… What are Physical Properties? Physical Properties are those properties that can be observed without changing the composition of the sample. What are some examples of Physical Properties? Melting point temperature, boiling point, color, hardness, density

Chemical Changes and Chemical Properties How can one describe a Chemical Change? A starting material (Reactant) is changed into a “new”* material (Product) with different properties. Generally, atoms are rearranged and bonded in a different way to form a “new” substance. *“new” = different How can one Identify a Chemical Change? The presence of a “new” material with different Properties is evidence of a Chemical Change. What are Chemical Properties? Chemical Properties are the Chemical Changes a substance may undergo. Describe the Chemical Change illustrated here. Oxygen and methane rearrange their atoms to form water and carbon dioxide.

Pure Substances What is an Element? What is a Compound? A sample of matter is an Element if it contains only one type of atom. Elements cannot be decomposed into anything simpler. *Except sub-atomic particles What is a Compound? Atoms of Different Elements may chemically bond together to form Compounds. What are the characteristics of a Compound? 1. Elements combine in a Definite Ratio due to specific bond formation. 2. The Physical and Chemical Properties of Compounds are Different from the Elements from which they form.

Most Materials are Mixtures What are the Characteristics of Mixtures? Substances (Elements and/or Compounds) can be Combined Without Chemically Bonding. 1. Therefore, the Proportions of components in a Mixture can vary. 2. The Substances retain their identity and the properties of the mixture are a blend of the properties of the individual components. Distinguish between Homogeneous vs. Heterogeneous Mixtures Homogeneous Mixtures have a uniform composition throughout. The Different Components can be seen in a Heterogeneous Mixture. What type of mixture is an Aqueous Solution (aq)? An Aqueous Solution is a Homogeneous Mixture. Water is the Solvent.

Methods to Classify Types of Matter

Classification of Matter All Matter Can it be separated by Simple Physical means? Yes No Mixture Pure Substance Can it be decomposed by Chemical means? Is the Composition Uniform? Yes No Yes No Homogeneous Mixture Heterogeneous Mixture Compound Element

Methods Used to Separate Different Parts of a Mixture Describe the process of Distillation. 1. The component with the Lowest Boiling Point Vaporizes Most Rapidly. 2. The Vapors Cool and Condense, and flow into a separate container. Describe the process of Centrifugation. Spinning a mixture causes the Denser Components to settle to the bottom faster.

More Methods of Separation of Components of a Mixture Describe the process of Filtration. Larger particles are trapped while smaller particles travel through a filter. Filter Paper will Not separate the components of an aqueous solution (aq). Describe the process of Paper Chromatography Pigments in a Mixture Separate due to different affinities for a specific Solvent as it travels up the paper.

Compounds vs. Mixtures Different components combined in a definite ratio….Why? Different components can combine in any ratio…..Why? Compounds make specific Chemical Bonds while Mixtures do not. Electrolysis: Using electricity to Decompose Water into its individual components Characteristics of mixtures are a combination or blend of characteristics of individual components….Why? Characteristics of compounds are different from individual components…..Why? Forming a Compound is a Chemical Change, thus a “new” material forms. Difficult to separate individual components….Why? Easy to separate individual components…Why? Chemical Bonds are Difficult to Break. Mixtures are Not Chemically Bonded.

Classify each of the following as one of the four types of matter Classify each of the following as one of the four types of matter. Explain each choice. Link to Quia Game: Types of Matter Iced Tea with lemon and sugar Pure Substance: Compound NaCl (l) Heterogeneous Mixture Air Solution = Homogeneous Mix. NaCl (aq) (aq) is ALWAYS a Homogeneous Mixture Sea Water Probably a Heterogeneous Mixture, possibly Homogeneous CO2 (g) Pure Substance: Compound Wood (oak) Heterogeneous Mixture Cheese Pizza Heterogeneous Mixture Carbon (s) Pure substance: Element Quartz Crystal (silicon dioxide) Pure Substance: Compound O2 (g) Pure substance: Element Paper Homogeneous Mixture Heterogeneous Mixture if made w/ real lemons Distilled Water Pure Substance: Compound Lemonade Tap Water Pure substance: Element Homogeneous Mixture Zinc Powder NaCl (s) Pure Substance: Compound Brass* Alloy: Homogeneous Mixture of Metals

Simple Particle Diagrams How can Simple Particle Diagrams Illustrate the Phases of Matter? Link to Phases of Matter in Containers Link to Phases of Matter at the Molecular Level Link to Interactive Phases of Matter How can Simple Particle Diagrams Illustrate the Types of Matter: Elements, Compounds, and Mixtures? Link to Examples of Elements, Compounds, and Mixtures (or see next slide) Link to Elements, Compounds and Mixtures Interactive Quiz

Describe the Types of Matter http://www.docbrown.info/page01/ElCpdMix/EleCmdMix.htm#images

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