1. Study Sheet for Chapter 2 Honors Biology

2. EXTENDED RESPONSE TIPS:
EXAMPLE:
Surface tension caused by the pulling in of H-bonds of the water molecules. This creates a “film” on the surface of the water.
This allows small insects to walk on the surface of water.

3. #1 Formula = abbreviation of a compound
Molecule = 2 or more atoms chemically bonded (can be same or different)
Atom = 1 unit – smallest unit of an element
Formula = abbreviation of a compound
Compound = 2 or more different elements bonded together chemically
Symbol = abbreviation of an element
Element = 1 kind of substance that cannot be broken down by chemical means – listed on Periodic table

4. #2 59 Co 27 Mass number = 59 Atomic number = 27 Number of protons = 27
Number of electrons = 27
Number of neutrons = 32

5. #3
Trace elements
Appear in very small amounts
Milligrams (mg)

6. #4 Radioactive isotope Breaks down spontaneously
(gives off energy and particles, can be detected on a PET scan)
Break down to their more stable form
EX: C-14 to C-12

7. #5 Why do atoms join to form compounds?
TO FILL THEIR OUTER ELECTRON SHELL

8. #6
IONS and ISOTOPES
IONS = differ in the number of electrons (charged atoms)
ISOTOPES = differ in the number of neutrons (different mass numbers)

9. #7 Electrons in covalent and ionic bonds
COVALENT = electrons are shared
IONIC = electrons are transferred (lost/gained)

10. #8 Solute and solvent and solution
Water = solvent – does the dissolving (larger amount)
Sugar = solute –being dissolved
Both = solution

11. #9
H-bonding
When water reaches 4oC and below H-bonds form an open lattice (less dense)
For surface tension, H-bonds pull the water molecules inward to form a “film”

12. #10 IN ORDER (strongest to weakest): COVALENT IONIC H-bonding
Van der Waals

13. #11
Buffers
Minimize the change in pH by adding extra H+ and OH-

14. #12 ACIDS put H+ ions into solution (H+ donors)
BASES put OH- ions into solution
(OH- donors)

15. #13
Water has high heat of vaporization (slow to heat and also slow to cool)
So the coastal area temperatures would change less rapidly than inland areas

16. #14 Strong 1-3 Weak 4-6 pH 3 = [H+] 10-3
ACIDS
BASES
Strong 1-3
Weak 4-6
pH 3 = [H+] 10-3
pH 4 is 100 X’s the H+ ions than pH 6
Strong 11-14
Weak 8-10
pH 11 = 10-11

17. #15
Electrons fill 2 8

18. #16
ACID PRECIPITATION
pH lower than 5.2

19. #17
COVALENT BONDS

20. #18
H+ ions surround Cl-
OH- ions surround Na+

21. #19
REACTANTS PRODUCTS
Left of arrow right of arrow

22. #20

23. #20
Elements that are located in the same column behave more alike chemically

24. #21 Polar Covalent = unequal sharing of e-
Nonpolar Covalent = equal sharing of e-

25. #22
Bohr Model

26. #23
H-H O-H NaCl

27. #24
UNIQUE PROPERTIES OF WATER
1. H-bonding
2. Polarity

28. #25
C H O N
Trace element in mg

29. #25 Fe I F used to prevent tooth decay
Used by RBC to carry oxygen in hemoglobin I
used to prevent blindness and have proper use of thyroid F
used to prevent tooth decay

30. #26
Elements have different numbers of protons
Elements have different numbers of electrons (form different ions and different bonds)

31. #26
Same column have same outer shell (valence) electrons

32. #27 ISOTOPES OF AN ELEMENT Same number of protons (same atomic number)
Different number of neutrons (different mass number)

33. #28
Valence electrons (fill inner shell first) 2 8

34. #29
If atomic number 8
Can form two more bonds

35. #30 BOTH INTERMOLECULAR Van der Waals = are momentary
very weak forces of attraction
between nonpolar molecules resulting from uneven electron distributions
(EX: gecko hairs on feet and glass)
H-bonding = forces between H and F, O, or N

36. #31
Cations = (+) ions
Anions = (-) ions

37. #32
You need to break the H-bonds to vaporize (form a gas)- takes extra time You need to form H-bonds to form ice – takes extra time

38. #33

39. Determine the pH If [H+] = 10-4 = pH 4 [OH-] = 10-10

40. #34
Mg Cl-
K+ I-
Ca P-3

41. #35 Ca = calcium C = carbon Co = cobalt
REVIEW YOUR ELEMENTS AND SYMBOLS:
Ca = calcium
C = carbon
Co = cobalt

42. #36 EXAMPLE Why water makes a nice drop on wax paper:
Surface tension on the water.
Strong cohesion of the water molecules
Weak adhesion to the wax paper.
Review blue sheet, water properties quiz and lab.