Chapter 1 Matter and Change pp. 4- 27

1. Chapter 1Matter and Changepp. 4- 27

2. Ch. 1 - Matter I. Introduction (p.5-7) What is Chemistry? Branches of Chemistry

3. What is Chemistry? • The study of the composition, structure, and properties of matter and the changes it undergoes. • Chemistry is a physical science. • A basic understanding of chemistry is central to all other sciences. • Chemistry is also central to our everyday lives.

4. Branches of Chemistry • Inorganic Chemistry - study of substances without carbon • Organic Chemistry - study of all substances containing carbon • Biochemistry- study of the chemistry of living organisms

5. Ch. 1 - Matter II. Classification of Matter (p.15-17, 397-398) Classifying Matter by Composition

6. Classifying Matter by Composition Homogeneous – matter with a uniform composition Heterogeneous - matter without a uniform composition Substance- A pure type of matter that does not vary from sample to sample. Includes elements and compounds

7. Classifying Matter by Composition • Elements- simplest kind of matter, made of one type of atom • An atom is the smallest unit of an element that maintains the properties of that element. • Cannot be broken down into simpler substances by ordinary chemical means • Ex. gold, copper, oxygen (on the periodic table)

8. Elements are Pure Substances • Element • composed of identical atoms • EX: copper wire, aluminum foil

9. Classifying Matter by Composition • Compounds – matter composed of the atoms of two or more elements chemically bonded • Compounds can be broken down by chemical methods • When they are broken down, the components have completely different properties than the compound. • Ex. Sugar, salt, water, carbon dioxide

10. Compounds are Pure Substances • Compound • composed of 2 or more elements in a fixed ratio • properties differ from those of individual elements • EX: table salt (NaCl)

11. Classifying Matter by Composition • A mixture is a blend of two or more kinds of matter, each of which retains its own identity and properties. • A mixture is mixed together physically. • Variable composition, often expressed by a percent composition by mass or volume (Ex. 5% salt and 95% water)

12. Classifying Matter by Composition • A heterogeneous mixture is not the same throughout (not uniform). • Examples: M & M’s, Chocolate chip cookie, gravel, soil, rocks such as granite, blood, milk, salad, ocean water, etc. • Homogeneous mixtures are also called solutions. Ex. Salt water and Kool –aid

13. Mixtures • Variable combination of 2 or more pure substances. Heterogeneous Homogeneous

14. Tyndall Effect Mixtures • Solution • homogeneous • very small particles • no Tyndall effect • particles don’t settle • EX: rubbing alcohol

15. Mixtures • Colloid • heterogeneous • medium-sized particles • Tyndall effect • particles don’t settle • EX: milk

16. Mixtures • Suspension • heterogeneous • large particles • Tyndall effect • particles settle • EX: fresh-squeezed lemonade

17. Mixtures • Examples: • mayonnaise • muddy water • fog • saltwater • Italian salad dressing colloid suspension colloid solution suspension

18. Classify It • Examples: • magnesium • Pizza • Calcium chloride • Orange juice • Club soda

19. Classify It element hetero. mixture compound hetero. mixture Homo. (solution) • Examples: • magnesium • pizza • Calcium chloride • Orange juice • Club soda

20. MIXTURE PURE SUBSTANCE yes no yes no Is the composition uniform? Can it be chemically decomposed? Composition of Matter Flowchart MATTER yes no Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element

21. Element Compound Mixture Classifying at the Molecular Level

22. Ch. 1 - Matter III. States of Matter (p.12) Classifying Matter by the Kinetic Molecular Theory States of Matter

23. Classifying Matter by Kinetic Molecular Theory • KMT • Particles of matter are always in motion. • The kinetic energy (speed) of these particles increases as temperature increases.

24. Four States of Matter • Solids • very low KE - particles vibrate but can’t move around • fixed shape • fixed volume

25. Four States of Matter • Liquids • low KE - particles can move around but are still close together • variable shape • fixed volume

26. Four States of Matter • Gases • high KE - particles can separate and move throughout container • variable shape • variable volume

27. Four States of Matter • Plasma • very high KE - particles collide with enough energy to break into charged particles (+/-) • gas-like, variableshape & volume • stars, fluorescentlight bulbs, CRTs

28. States of Matter Definite Volume? Definite Shape? Particle position and movement Packed tightly, vibrate about fixed pt Solid YES YES Close together, can move past each other - flow Liquid NO YES Far apart, move rapidly - flow Gas NO NO

29. Ch. 1 - Matter IV. Properties & Changes in Matter (p.11-14) Extensive vs. Intensive Physical vs. Chemical

30. Extensive vs. Intensive • Extensive Property • depends on the amount of matter present • Intensive Property • depends on the identity of substance, not the amount

31. Extensive vs. Intensive • Examples: • boiling point • volume • mass • density • conductivity intensive extensive extensive intensive intensive

32. Physical vs. Chemical • Physical Property • can be observed without changing the identity of the substance • Chemical Property • describes the ability of a substance to undergo changes in identity

33. Physical vs. Chemical • Examples: • melting point • flammable • density • magnetic • tarnishes in air physical chemical physical physical chemical

34. Physical vs. Chemical • Physical Change • changes the form of a substance without changing its identity • properties remain the same • Chemical Change • changes the identity of a substance • products have different properties

35. Condense Freeze Evaporate Melt Physical Changes in Matter Gas Liquid Solid

36. Physical Changes in Matter • Sublimation is a process in which a solid changes directly to a gas without going through the solid phase.

37. Physical vs. Chemical • Examples: • rusting iron • dissolving in water • burning a log • melting ice • grinding spices chemical physical chemical physical physical

38. Indications of chemical change 1 Production ofheat, light, sound, or electricity 2.)Production of agas 3.)Formation of aprecipitate 4.)A change incolor 5.)A change inodor

39. Separating Mixtures Mixtures are separated by their physical properties. Primary methods of separating mixtures are: filtration distillation centrifuge chromatography

40. Separating Mixtures • Filtration is a method used to separate the components of mixtures that contain an insoluble solid and a liquid. Example: sand and water

41. Separating Mixtures • Distillation is a method of separating substances in a mixture by evaporation of a liquid and subsequent condensation of its vapor. Example: desalination of salt water

42. Separating Mixtures • Centrifuge (see p. 16) • Used to separate solid-liquid mixtures such as those in blood. The centrifuge spins rapidly and causes the solid to settle to the bottom. • Ex. Separating blood

43. Separating Mixtures Chromatography is a method of separating mixtures that uses a stationary phase and a mobile phase. Paper chromatography can be used to separate pigments because they move at different rates on the paper.

44. Ch. 1 - Matter V. Elements (p.20-24) Extensive vs. Intensive Physical vs. Chemical

45. Elements • There are 92 naturally occurring elements • Each has a 1 or two letter symbol • First letter always capitalized second letter is lower case

46. Elements • The periodic table shows the elements organized by their chemical properties • Columns on the table represent groups or families of elements with similar chemical properties • Properties vary across the horizontal rows or periods

47. Elements • Three general classes of elements are metals, nonmetals, and metalloids. Metals are on the left and in the center of the periodic table. Nonmetals are on the right. Metalloids are on the zig-zag dividing line.

48. Metals

49. Nonmetals

50. Semi-metals or Metalloids