1. The Chemistry of Life: Atoms and Molecules

2. Periodic Table 112 known elements
Pure substances that cannot be broken down into simpler chemical entities by ordinary chemical reactions.
Periodic Table 112 known elements

4. Major Elements Comprising the Biological Molecules of Living Things
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur

6. Elements & Atoms
An element is composed of atoms (0.1-1 nm in diameter)
Atom cluster of small particles (proton, neutron, electron)

7. Subatomic Particles
Protons (p +)
Neutrons (n o)
Electrons (e -)

8. Electron Shell Configurations of Atoms
proton
neutron
electron
hydrogen
atom
helium
atom
carbon
atom
1p, 0n, 1e-
2p, 2n, 2e-
6p, 6n, 6e-

9. atomic number: number of p; #p = #e- 2He2e- and 2p

10. atomic mass (atomic wt.): sum of masses of p+n
He 2p + 2n, atomic mass = 4 4
2He He
p + n e-

11. Carbon Atom C
p =
n =
e- =
Atomic number =
Atomic mass =

12. Isotope C
atoms that differ in the number of neutrons 12
6 C 13
6 C 14
6 C
C12 C13 C14
stable stable isotope unstable- radioactive isotope

13. Two or more atoms held together by chemical bonds
Molecule
Two or more atoms held together by chemical bonds
Oxygen O2
Nitrogen N2
Ammonia NH3
Carbon Dioxide CO2
Water H2O
Methane CH4
Glucose C6H12O6

14. Compound
Binding two or more different kinds of elements together
NaCl +
C6H12O6

15. Compound
Binding two or more different kinds of elements together
NaCl
CH4
C6H12O6

16. Ion
An atom that has either gained or lost electrons such that it exhibits a net charge
Na+
Cl-

17. Sodium (Na) Atom
11 P+
12 No

18. Sodium (Na+) Ion +
11 P+
12 No

19. Chlorine (Cl) Atom
17 P+
18 No

20. Chloride (Cl-) Ion _
17 P+
18 No

21. Some Examples of Ions Hydrogen H+ Potassium K+ Fluoride F-
Calcium Ca+2
Magnesium Mg+2

22. Complex Ions Hydroxide OH- Bicarbonate HCO3- Nitrate NO3-
Phosphate PO4-3
Ammonium NH4+
Acetate C2H3O2-

23. Bond Types:
Ionic
Covalent
Hydrogen

24. Ionic Bonds
Transfer of electron
11 P+
12 No
17 P+
18 No

25. Covalent Bonding: electron sharing

26. Covalent Bonding: electron sharing

27. Hydrogen Bonding Between Water Molecules
Covalent
bond

28. Hydrogen Bonding Between Different Molecules

29. Examples of Organic Molecules
Lipids
Carbohydrates
Proteins
Nucleic acids

30. Properties of Water
High heat capacity-absorbs and releases large amounts of heat (land heats faster than water)
High heat of vaporization- sweat, cooling mechanism
Polarity solvent properties- universal solvent
Reactivity- hydrolysis and condensation (dehydration)

31. Polarity of Water Molecules

32. Chemical Reactions
A  B
reactant  product

33. Chemical Synthesis
A + B  AB

34. Chemical Decomposition
AB  A + B

35. Chemical Rearrangement
AB + CD  AC + BD

36. Decomposition of Water
H2O  OH- + H+ O O + H H H H
Water molecule
[H2O]
Hydroxyl ion
[HO-]
Hydrogen ion
[H+]

37. pH “p” stands for potential and “H” stands for hydrogen
Refers to the potential of a substance to attract hydrogen ions (H+)

38. Acids HCl  H+ + Cl- Proton donor, i.e., they donate H+ ions
HCl is a strong acid with a pH 1-2
HCl  H+ + Cl-

39. Bases Na+ + OH-  NaOH NH3 + H+  NH4 OH - + H+  H2O HCO3 +H+  H2CO3
Proton acceptor, i.e., they take up H+ ions
NaOH is a strong base ~pH 12
Na+ + OH-  NaOH
NH3 + H+  NH4
OH - + H+  H2O
HCO3 +H+  H2CO3

40. Neutralization
HCl + NaOH H2O + NaCl

41. Buffer- resists dramatic changes in pH; ex
Buffer- resists dramatic changes in pH; ex. tums, rolaids…buffers stomach acid

42. pH Scale Type of Solution pH Value Neutral 7 Acidic 0-6
0-14
Type of Solution
pH Value
Neutral 7
Acidic 0-6
Basic (alkaline) 8-14

43. pH Scale
Logarithmic scale
blood

44. Measuring pH

45. pH of Coke

46. Impact of Acid in our Body-
CO2 + H2O H2CO HCO 3 + H+ O2
Bicarbonate
Carbonic acid
Capillary
Cell
CO2 O2

47. Impact of Acid in our Body
HCl
pH 1-2

48. Impact of Acid in our Body
pH 8

49. Impact of Acid in the Ocean

50. Inquiry How many neutrons in 7 N? 14
Of the following pH’s which is most acidic?
3. The symbols K, Na, C, and S are:
4. Which of the following are elements?
water; sugar; table salt; the atmosphere
5. Which of the following are pure substances?
wine; seawater; blood; iron 14