1. Chapters 3 - 4 – The Chemical Context of Life

3. Matter: takes up space and has mass

4. Matter 3 states

5. Elements

6. Iron Carbon Tellurium Elements

7. Atomic structure Atom is the smallest unit of matter (an element) that still retains properties of an element

8. Atomic structure Compound 2 or more elements bonded together

9. Atomic structure Molecule Smallest particle of a substance composed of at least 2 atoms water oxygen a sugar

10. Four elements make up 96% of living matter Atomic structure

11. All matter is composed of atoms Atomic structure

12. Atom are composed of subatomic particles Protons (+) Neutrons (0) Electrons (-) Atomic structure

13. Proton (Positive charge) Neutron (No charge) Electron (Negative charge) Hydrogen 1 Proton 1 Electron Oxygen 8 Protons 8 Neutrons 8 Electrons

14. Atomic structure

15. Atomic number Atomic mass Atomic structure

16. Atomic number = # of protons Atoms with the same atomic number belong to the same element, and thus have the same inherent properties. Atomic structure

17. Nucleus Electrons Cloud of negative charge (2 electrons) Electrons e-

18. Electrons Potential Energy Chemical reactions

19. Hydrogen - 1 Oxygen - 8

20. Electron shell Electron shell is an energy level in which electrons reside 1 st shell: maximum 2 electrons 2 nd shell: maximum 8 electrons 3 rd shell: maximum 8 electrons 4 th & 5 th shells: 18 electrons Atoms are most stable when outer shell is filled

21. Electron shell diagrams

22. Few openings in outer shell Chlorine

23. More openings in outer shell Carbon

24. Neon 10 Ne Argon 18 Ar Helium 2 He Filled outer shell

25. Atoms tend to react in ways that allow them to fill their outer shell –Most elements found in living systems react to gain 8 electrons in their outer shells Octet rule

26. No open slots – very stable Open slots – reactive

27. Electrons Potential Energy Chemical reactions

28. Third energy level (shell) Second energy level (shell) First energy level (shell) Atomic nucleus Energy absorbed Energy lost Electrons and energy

30. Potential energy

31. Potential energy released Energy put to work

32. Electrons and energy

33. Electrons Potential Energy Chemical reactions

34. Chemical Bonds

35. A. Covalent bond B. Ionic bond C. weak chemical bonds Chemical Bonds

36. Hydrogen atoms (2 H) Hydrogen molecule (H 2 ) Covalent Bond

37. Hydrogen

38. Oxygen (O 2 ) Water (H 2 O) Methane (CH 4 ) Covalent Bond

39. Some atoms can form more than one bond. –Hydrogen: one bond –Oxygen: two bonds –Nitrogen: three bonds –Carbon: four bonds Covalent Bonds

40. Polar covalent bonds bond in which electrons are shared unequally.

41. Na + Cl – Ionic Bonds

42. Na Sodium atom (an uncharged atom) Cl Chlorine atom (an uncharged atom)

43. Na + Sodium ion (a cation) Cl – Chlorine ion (an anion) Ions + -

44. Na + Sodium ion (a cation) Cl – Chlorine ion (an anion) Ions + - Ion: A atom carrying a electric charge which is formed either by gaining or losing electrons.

45. Na + Sodium ion (a cation) Cl – Chlorine ion (an anion) Sodium chloride (NaCl) Ionic bond

46. Na Sodium atom (an uncharged atom) Cl Chlorine atom (an uncharged atom) Na + Sodium ion (a cation) Cl – Chlorine ion (an anion) Sodium chloride (NaCl) Ionic bonding

47. Weak chemical bonds

48. Hydrogen bonds Van der Waals Weak chemical bonds

49. –– ++ Oxygen Hydrogen Bohr model 8+ 8n + + –– ++ Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hydrogen bonds

50. Unstable hydrogen bonds Water molecules Liquid water Hydrogen bonding

51. –– Water (H 2 O) Ammonia (NH 3 ) Hydrogen bond ++ ++ –– ++ ++ ++ Hydrogen bonding

52. Water (H 2 O) Methane (CH 4 ) 104.5° Molecules have shape

53. Natural endorphin Morphine Structures of endorphin and morphine Shape and Function

54. Natural endorphin Morphine Brain cell Endorphin receptors Shape and Function

55. ReactantsReactionProducts 2 H 2 OO2O2 2 H 2 Chemical Reactions

56. Energy and Chemical Reactions