Chapters 1 and 2

1. Chapters1 and2 Matter andChange

2. Matter and ItsProperties Matter: • Anything that has mass and volume is considered to be a form ofmatter Mass: • The amount of matter in anobject. • Volume: • The space that matter takesup.

3. Properties and Change inMatter • PhysicalProperties: • can be observed andmeasured without changing the substance’scomposition.

4. PhysicalProperties • Describe physical characteristics of substances • Size, shape, color • Conductivity • Density • Meltingpoint • Boilingpoint • Malleability • Ductility

6. States of Matter

7. PhysicalChanges • Changes the appearance, without changing the composition of thematter. • Melting, dissolving, ­boiling

8. Phase Changes are PhysicalChanges • Solid: definite volume andshape • Liquid: definite volume, indefiniteshape • gas: indefinite volume andshape vaporization melting condensation freezing Gas Liquid Solid

9. Chemical Properties • Describe how a substance may react or chemically change. • Flammable • Toxic • Acidic • Explosive • Corrosive • Oxidizer

10. Physical Changes • Physical changes do NOT result in a new substance. For example: • Changes in shape • Changes in state like freezing or boiling • Some Dissolving (like sugar).

11. Physical Change We say that a physical change is one in which: • there are no new substances formed • the original substance(s) may be reclaimed by a physical process (i.e. evaporation) • The substance retains many of its chemical and physical properties

12. Chemical Changes • A chemical change is one in which there is a new material made.

13. Chemical Changes ALWAYS involve the creation of NEW SUBSTANCES.

14. Chemical Changes • Clues that a chemical change has occurred.

15. Chemical Changes #1 A new COLORappears that wasn’t there before.

16. Is bleaching a chemical change or a physical change?

17. Chemical Changes #2Change in temperature: The change must occur from within the substance, with no external heat source. after chemical reaction Before chemical reaction

18. Chemical Changes #3 A new gas forms that was not there before.

19. Chemical Changes #3 A new gas forms that was not there before. For example: Baking Soda + Vinegar = Carbon Dioxide Gas Remember: Boiling a liquid into a gas is NOT chemical!

20. Lead sulfate and potassium iodide react to form a yellow solid call lead iodide. The precipitate is a new substance that was not there before. #4 Formation of a precipitate: a solid formed from the reaction of two solutions. Chemical Changes

21. Try This Example: • You observe a wax candle burning. • List all the physical changes and signs of chemical change.

22. Classification of Matter What are Mixtures?

23. Mixtures • Made up of two or more substances physically combined. Each part keeps its own individualproperties. • Examples:Air, wood, tea, • Consist of more than one kind of matter. Do not have a chemical formula.

24. Orange juice is a mixture of: Water – H2O Fructose – C6H12O6 Citric Acid–C6H8O7 and manymore compounds… Most thingsaround us aremixtures

25. Mixtures • Heterogeneous: • Non­uniform composition. Chocolate chip cookie, gravel, soil. • Homogeneous: • Same composition throughout. Kool­aid, air, tea calledsolutions.

26. Solutions • Homogeneous mixture­ called asolution • Mixed molecule bymolecule • Can occur between any state ofmatter. • Solid in liquid­Kool­aid • Liquid in liquid­ 3% hydrogenperoxide • Gas in gas­air • Liquid in gas­ clouds • Gas in liquid­ softdrink • Solid in solid ­brass

27. SeparatingMixtures

28. SeparatingMixtures • Components are physicallymixed • Use differences in the physical properties of components of the mixture to separate themixture • Solubility • Density • Boilingpoint • Molecularstructure

29. Decanting

30. Filtering

31. Magnetism

32. Distillation Used to separate a liquid mixture using boiling points. Acetone has a lower boiling point than water.

33. Chromatography • A mixture moves through a medium in which the components move at different rates.

38. Evaporation

39. Classification of Matter PureSubstances

40. Classification ofMatter • Pure substance pure form of matter ­ consists of – an element or a compound. Has a chemicalformula. • Carbon dioxide –CO2 • Hydrogen –H2 • Sodium –Na • Water –H2O

41. PureSubstances?

42. Basic Building Blocks of Matter- Atoms ­ Elements ­Compounds • Atoms: • are the basic units ofmatter • The smallest unit of an element that maintains the properties of thatelement.

43. Basic Building Blocks of Matter Atoms ­ Elements ­Compounds • Elements: • pure substances made ofonly one type or kind ofatom • Na H2 Pb O2 S8

44. Most of the elements donot exist in their elemental state, but exist in compounds. Why do you think thisis? 2Na+Cl2 2NaCl

45. Compounds • Substances made from the chemical bonding of two or moredifferent elements. (NaCl H2O MgO) • Substances that can only be broken down by chemicalmethods. • Has completely different chemical and physical properties from the constituent elements that make itup.

46. Vocabulary • Molecule • two or more atoms bonded (connected), identical or different atoms • Compound • – two or moredifferent • kinds ofatoms Molecule of water

47. MATTER yesCanit beseparatedno by physicalmeans? MIXTURE PURESUBSTANCE yes no yes no Is thecomposition uniform? Can it bedecomposed by chemicalmeans? Homogeneous Mixture (solution) Differentatoms: Compound Sameatoms: Element Heterogeneous Mixture

48. Which isit? PURE SUBSTANCE? MIXTURE? ELEMENT? MOLECULE? COMPOUND?

49. Which isit? PURE SUBSTANCE? MIXTURE? ELEMENT? MOLECULE? COMPOUND?

50. Which isit? PURE SUBSTANCE? MIXTURE? ELEMENT? MOLECULE? COMPOUND?