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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.
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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 Atom = 1 unit – smallest unit of an element Molecule = 2 or more atoms chemically bonded (can be same or different) 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
#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)
#7 • Electrons in covalent and ionic bonds • COVALENT = electrons are shared • IONIC = electrons are transferred (lost/gained)
#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) • For surface tension, H-bonds pull the water molecules inward to form a “film”
#10 • IN ORDER (strongest to weakest): • COVALENTIONICH-bonding Van der Waals
#11 • Buffers • Minimize the change in pH by adding extra H+ and OH-
#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 ACIDS BASES Strong 11-14 Weak 8-10 pH 11 = 10-11 • Strong 1-3 • Weak 4-6 • pH 3 = [H+] 10-3 • pH 4 is 100 X’s the H+ ions than pH 6
#15 • Electrons fill • 2 • 8 • 8
#16 • ACID PRECIPITATION • pH lower than 5.2
#17 • COVALENT BONDS
#18 • H+ ions surround Cl- • OH- ions surround Na+
#19 • REACTANTS PRODUCTS • Left of arrow right of arrow
#20 • Elements that are located in the same column behave more alike chemically
#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 • CHON • Trace element in mg
#25 • 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 • 8
#29 • If atomic number 8 • Can form two more bonds
#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 • Anions = (-) ions
#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
Determine the pH • [H+] [OH-] = 10-14 • If [H+] = 10-4 = pH 4 • [OH-] = 10-10
#34 • Mg-2 Cl- • K+ I- • Ca+2 P-3
#35 • REVIEW YOUR ELEMENTS AND SYMBOLS: • Ca = calcium • C = carbon • Co = cobalt
#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.