2. Warm-Up (9/26) (1.) List and describe in detail the 5 components that make up a good science lab report. (2.) Write the following in scientific notation: a.) 0.00076 g b.) 345,900,000 L c.) 82.1 m (3.) Convert the following measurements: a.) 23 m  cm b.) 9.48 mL  dL c.) 7.6 Mg  pg

3. Answers to Warm-Up (9/26) (1.) Introduction, Materials, Procedures, Data Table, Conclusion (2.) a.) 7.6 x 10 -4 g b.) 3.459 x 10 8 L c.) 8.21 x 10 1 m (3.) a.) 2.3 x 10 3 cm b.) 9.48 x 10 -2 dL c.) 7.6 x 10 18 pg

4. Chapter 2 Matter and Change Ms. Riggins Lawndale High School

5. Chapter 2.1 – Properties of Matter Properties used to describe matter can be classified as extensive or intensive

6. Extensive and Intensive Extensive – depends on the amount of matter in a sample (mass or volume) Intensive – depends on the type of matter in a sample (hardness/softness)

7. Practice Classify the following properties as extensive or intensive 5 pounds of apples Glass Jar 2 miles long Plastic Box Odor

8. Identifying Substances Physical Property – a quality of a substance that can be observed or measured (color, hardness, shape, state of matter, boiling temperature) Every sample of the same substance has identical intensive properties because every sample has the same composition

9. States of Matter Solid – form of matter that has a definite shape and volume

10. States of Matter Liquid – form of matter that has an indefinite shape with a definite volume (usually flows)

11. States of Matter Gas – form of matter that has an indefinite shape and volume (takes the shape and volume of its container

14. Physical Changes Physical Change – when properties of a material change, but the composition does not change Examples – break, split, cut, crush, boil freeze, melt, condense Physical changes can be reversible (melting) or irreversible (cutting hair, filing nails, cracking an egg)

15. Chemical Change Chemical Change – a change that produces matter with a different composition than the original matter Example – heating can be used to break down some compounds into new compounds, or electricity can break down water into hydrogen and oxygen

16. Chapter 2.2 - Mixtures A physical blend of two or more components

17. 2 Types of Mixtures (1.) Homogeneous – a mixture in which the composition looks the same throughout (also known as solution) For example: oil or vinegar separately (2.) Heterogeneous – a mixture in which the composition does NOT look the same throughout (chicken soup, salad, oil & vinegar mixed together)

18. Separating Mixtures You can use a variety of methods to separate mixtures depending on the substances and their physical properties. Filtration – process that separates a solid from a liquid in a heterogeneous mixture (cooked pasta in a colander, coffee grounds to make coffee) Distillation – a process involving liquid being boiled to produce a vapor, which is then condensed back to a liquid

19. Chapter 2.3 - Elements and Compounds Element – simplest form of matter (oxygen, carbon, nitrogen) Compound – substance that contains two or more elements chemically combined together

20. Elements vs. Compounds Compounds can be broken down into simpler substances, but elements cannot Compound = H 2 O Elements = 2 hydrogen’s 1 oxygen

21. Substances vs. Mixtures Substance – composition of a material is fixed (Elements and Compounds) Mixture – composition of a material varies (Homogeneous and Heterogeneous Mixtures)

22. Practice Classify the following materials as element, compound, or mixture Table Salt (NaCl) Salt Water Sodium (Na)

23. Chemical Symbols Chemists use chemical symbols to represent elements, and chemical formulas to represent compounds Each element is represented by a 1- or 2-letter chemical symbol The 1 st letter is always CAPITALIZED, while the 2 nd letter (if used) is lowercase. (Example: H, O, C, Cl, He, Na)

24. Chemical Formulas Anytime subscripts are used in a formula, they indicate the number of elements in the compound How many atoms does each formula contain? NaOH BaCr 2 O 7 C 12 H 22 O 11 HC 2 H 3 O 2 Mg(OH) 2

25. Chapter 2.4 – Chemical Reaction During a physical change, physical properties change. During a chemical change, chemical properties change. The result of a chemical reaction can produce a physical or chemical change, or both

26. Physical Changes During a physical change, properties of a material change, but the composition of the material does not. Physical Changes include… BOILING MELTING FREEZING CONDENSING BREAKING CUTTING CRUSHING

27. Chemical Change A change that produces matter with a different composition than the original matter

28. Chemical Reaction One or more substances changes into one or more new substances

29. Reactant versus Product Reactants - Substance present at the beginning of the reaction (left side) Products - Substance present at the end of the reaction (right side) Reactant  Product 

30. (1.) Transfer of energy (heat) (2.) Change in color (3.) Produces a gas (bubbles) (4.) Forms a precipitate (solid that forms and settles out of a liquid mixture) How to Recognize a Chemical Change

31. Conservation of Mass During any physical or chemical reaction, the mass of the reactants and products is conserved (stays the same) Example: 10 grams of ice melts into 10 grams of water Law of Conservation of Mass – mass of the products is always equal to the mass of the reactants (mass is neither created nor destroyed)

32. Classwork Sec 2-1 #’s 5, 8 Sec 2-2 #’s 11, 14, 16, 17 Sec 2-3 #’s 20, 21, 24, 25, 26, 27 Sec 2-4 #”s 29, 30, 31, 32, 33, 34