Study Sheet for Chapter 2 Honors Biology

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.

#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

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

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

#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

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

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

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

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

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

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

#11 Buffers Minimize the change in pH by adding extra H+ and OH- buffer animation pH of blood = 7.4

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

#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

#14 BASES ACIDS 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 pH 6 is 1000 X’s more H+ ions than pH 9

#15 Electrons fill 2 8 e- fill inner shells first

#16 ACID PRECIPITATION pH lower than 5.2

#17 COVALENT BONDS – electrons are shared

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

#19 REACTANTS PRODUCTS Left of arrow right of arrow

#20

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

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

#22 Bohr Model

#23 H-H O-H NaCl

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

#25 C H O N Trace element in mg

#25 trace elements in mg (small amounts) Fe 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

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

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

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

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

#29 If atomic number 8 Can form two more bonds How many e- do you need to fill the outer shell= number of bonds to form

#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

#31 Cations = (+) ions Ca +2 Anions = (-) ions F-

#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

#33

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

#34 Mg-2 Cl- K+ I- Ca+2 P-3

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

#36 INTERMOLECULAR FORCES Holding ionic compounds IONIC Holding nonpolar molecules Van der Waals Water to water H-bonds Polar molecules (No H) Van der Waals

#37 INTRAMOLECULAR FORCES A. cations and anions IONIC B. unequal sharing of e- POLAR COVALENT C. Equal sharing of e- NONPOLAR COVALENT D. When e- are transferred IONIC