Matter - Properties and Change: Physical & Chemical Changes, Classification of Matter, Separating Mixtures

1. Table of Contents Chapter 3: Matter— Properties and Change Physical & Chemical Changes Classification of Matter Separating Mixtures

2. Review • Without looking at your notes, list as many physical properties as you can • You could have included… • Hardness, • solubility, • density, • melting point, • electrical conductivity, • boiling point, • and physical state (solid, liquid, or gas).

3. Table of Contents Chapter 3: Matter— Properties and Change Physical and Chemical Changes

4. Matter—Properties and Change: Basic Concepts Physical Changes - Physical changes: Changes which alter a substance without changing its composition ex) Crumpling of a sheet of aluminum foil. • Why is that a physical change? • While the foil goes from a smooth, flat, mirror-like sheet to a round, compact ball, the actual composition of the foil is unchanged—it is still aluminum

5. Matter—Properties and Change: Basic Concepts Physical Changes • The state of matter depends on the temperature and pressure of the surroundings. - States: solid, liquid, gas,

6. Chemistry and Matter: Basic Concepts Chemical Changes • A chemical property always relates to a chemical change • Chemical change: the change of one or more substances into other substances • chemical change = chemical reaction.

7. Chemical Reactions and Equations: Basic Concepts Recognizing Chemical Reactions • A few clues that indicate when chemical reactions occur: • Change in… • temperature • color • odor • appearance (ex. phase)

8. Matter—Properties and Change: Basic Concepts Chemical Changes • Terms like • explode, rust, oxidize, corrode, tarnish, ferment, burn, rot, • refer to chemical reactions in which reactant substances produce different product substances.

9. TRY IT OUT! Identify each of the following as an example of a chemical change or a physical change. • Moisture in the air forms beads of water • on a cold windowpane. Physical B. An electric current changes water into hydrogen and oxygen. Chemical C. Yeast cells in bread dough make carbon dioxide an ethanol from sugar. Chemical balloon

10. Table of Contents Chapter 3: Matter— Properties and Change Classification of Matter We need to be able to distinguish between different types of matter Simpler? See Zach, General, 09-10, 02 Matter Classification, 01 Classification of Matter, ppt

11. You picked up this handout (right?) MATTER Heterogeneous materials Homogenous materials Mixtures SAME Substances Homogeneous mixtures (Solutions) Heterogeneous mixtures Chemical change Physical change Elements Compounds

12. Logic Chart N Y Q1? N Y Q2? N Y Q3? water, salt, sand

13. QUESTION 1: Is there more than 1 phase? • YES – heterogeneous mixture • A mixture: a combination of two or more substances in which the basic identity (properties) of each substance is not changed. • individual substances remain distinct. • Cloudy or nontransparent – 2 phases • ex) sand and water • NO – homogenous

14. Q2: If homogenous, more than 1 type of substance? • YES – homogenous mixture (solution) • Uniform throughout – 1 phase • Usually transparent • Separated by physical means (substances cannot) • Often have more than 1 version (gasoline, milk, etc.) • ex) salt water • NO – substance: (element or compound)

15. Q3: If substance, is there more than 1 type of atom? • NO – element • a pure substance that cannot be separated into simpler substances • YES – compound • a combination of different elements that are combined chemically. • can be broken down into simpler substances by chemical means

16. Logic Chart N Y More than 1 phase? N Y More than 1 type of substance? N Y More than 1 type of atom?

17. - Chemical property = observed by creating a new substance - Physical property = defines each substance MATTER Contains more than 1 phase Contains 1 phase Heterogeneous materials Homogenous materials Mixtures SAME Substances Homogeneous mixtures (Solutions) Heterogeneous mixtures Unique physical & chemical properties Chemical change Physical change Elements Compounds Solute = Solvent = Aqueous = dissolved dissolver water is solvent Composed of 1 type of atom 2 or more atoms bonded together

18. Additional Assessment Questions Practice Identify each of the following as an example of an element or a compound. A. sucrose (table sugar) compound element B. the helium in a balloon compound C. baking soda element D. a diamond

19. Matter—Properties and Change: Additional Concepts Mixtures Heterogeneous mixtures or homogenous mixtures? Sand in water Salt in water Separated by physical method mixed, not reacted boiling

20. Practice Identify each of the following as an example of a homogeneous mixture or a heterogeneous mixture. • 70% isopropyl rubbing alcohol homogeneous B. a pile of rusty iron filings heterogeneous heterogeneous C. concrete D. saltwater homogeneous E. gasoline homogeneous heterogeneous F. bread

21. Table of Contents Chapter 3: Matter— Properties and Change Separating Mixtures Heterogeneous and Homogenous mixtures can be separated by physical means

22. Mixtures – Separation Techniques 1) Filtration uses a porous barrier to separate a solid from a liquid. Heterogeneous mixtures 2) Distillationis based on differences in the boiling points of the substances involved Homogenous mixtures

23. Mixtures – Separation Techniques 3) Crystallizationresults in the formation of pure solid particles of a substance - the substance was originally dissolved 4) Chromatographyseparates the components of a mixture by their tendency to travel across the surface of another material