1. Chapter 2 The Chemical Context of Life

4. Fig. 2-3 Sodium Chlorine Sodium chloride

6. Table 2-1

7. (a) Nitrogen deficiency Fig. 2-4 (b) Iodine deficiency

11. Cloud of negative charge (2 electrons) Fig. 2-5 Nucleus Electrons (b) (a)

16. Fig. 2-8 (a) A ball bouncing down a flight of stairs provides an analogy for energy levels of electrons Third shell (highest energy level) Second shell (higher energy level) Energy absorbed First shell (lowest energy level) Atomic nucleus (b) Energy lost

18. Fig. 2-9 Hydrogen 1 H Lithium 3 Li Beryllium 4 Be Boron 5 B Carbon 6 C Nitrogen 7 N Oxygen 8 O Fluorine 9 F Neon 10 Ne Helium 2 He Atomic number Element symbol Electron- distribution diagram Atomic mass 2 He 4.00 First shell Second shell Third shell Sodium 11 Na Magnesium 12 Mg Aluminum 13 Al Silicon 14 Si Phosphorus 15 P Sulfur 16 S Chlorine 17 Cl Argon 18 Ar

21. Fig. 2-10-1 Electron-distribution diagram (a) Neon, with two filled shells (10 electrons) First shell Second shell

22. Electron-distribution diagram (a) (b) Separate electron orbitals Neon, with two filled shells (10 electrons) First shell Second shell 1 s orbital Fig. 2-10-2

23. Electron-distribution diagram (a) (b) Separate electron orbitals Neon, with two filled shells (10 electrons) First shell Second shell 1 s orbital 2 s orbital Three 2 p orbitals x y z Fig. 2-10-3

24. Electron-distribution diagram (a) (b) Separate electron orbitals Neon, with two filled shells (10 electrons) First shell Second shell 1 s orbital 2 s orbital Three 2 p orbitals (c) Superimposed electron orbitals 1 s , 2 s , and 2 p orbitals x y z Fig. 2-10-4

27. Fig. 2-11 Hydrogen atoms (2 H) Hydrogen molecule (H 2 )

30. Fig. 2-12 Name and Molecular Formula Electron- distribution Diagram Lewis Dot Structure and Structural Formula Space- filling Model (a) Hydrogen (H 2 ) (b) Oxygen (O 2 ) (c) Water (H 2 O) (d) Methane (CH 4 )

33. Elements with Electronegativity Values: http://www.green-planet-solar-energy.com/electronegativity-values.html

35. Fig. 2-13  –  +  + H H O H 2 O

37. Fig. 2-14-1 Na Cl Na Sodium atom Chlorine atom Cl

38. Fig. 2-UN6 Ionic bond Electron transfer forms ions Na Sodium atom Cl Chlorine atom Na + Sodium ion (a cation) Cl – Chloride ion (an anion)

41. Fig. 2-15 Na + Cl –

44. Fig. 2-16    +  +    +  +  + Water (H 2 O) Ammonia (NH 3 ) Hydrogen bond

45. Fig. 2-UN9

49. Fig. 2-17 s orbital Three p orbitals (a) Hybridization of orbitals Tetrahedron Four hybrid orbitals Space-filling Model Ball-and-stick Model Hybrid-orbital Model (with ball-and-stick model superimposed) Unbonded electron pair 104.5º Water (H 2 O) Methane (CH 4 ) (b) Molecular-shape models z x y

51. Fig. 2-18 (a) Structures of endorphin and morphine (b) Binding to endorphin receptors Natural endorphin Endorphin receptors Morphine Brain cell Morphine Natural endorphin Key Carbon Hydrogen Nitrogen Sulfur Oxygen

53. Fig. 2-UN2 Reactants Reaction Products 2 H 2 O 2 2 H 2 O

55. Fig. 2-19

57. Fig. 2-UN7

58. Fig. 2-UN11