2005-2006 P.O.D.s == GSLG ---- 21 OCT 2005 Atomic PODs: [show graphic of box from Periodic Table for Potassium] Q. What is the name of this element? A. K Q. How many neutrons are in the nucleus? A. 20 Q. How many electrons are in an atom of this element? A. 19 -- 24 OCT 2005 Periodic PODs: Q. Which element has 16 protons in its nucleus? A. Sulfur Q. In which period and group is Al? A. Period 3; Group 13 Q. How many electron enrgy levels are in an atom of potassium? A. four (4) -- 25 OCT 2005 Q. How many neutrons are in an atom of Ti? A. 6 Q. Draw a Bohr model of a Boron atom. Boron! A. Nucleus: 5(+),6(=); Electron "cloud": 5(-) -- 26-27 OCT 2005 Q. How many neutrons are in an atom of Ar? A. 22 Q. How many neutrons are in an atom of C-14? A. 8 (rather than 6) -- 28 OCT 2005 Q. List the protons, neutrons, and electrons for an isotope of Carbon, e.g., C-14. A. 6 P, 8 N, 6 E Q. Draw a Bohr model of a Na atom. A. 11 P, 12 N, 11 E Q. List the P,N,E for a Na ion. A. 11 P, 12 N, 10 E -- 03 NOV 2005 Q. List at least two ways elements are arranged on the Periodic Table. A. increasing Atomic Number; by period & group; same no. outer electrons/similar properties -- 15 NOV 2005 Reacto-POD Q. List at least two (2) clues that a chemical change may have occurred. A. temperature change (endo-, exo-); color change; gas production; precipitate formation -- 16 NOV 2005 Reacto-POD Q. Mr. Sanford buys a "hot pack" for his aching back. The pack is the kind you put in a microwave oven. What causes the pack to get to get hot -- a chemical- or physical change? A. Physical change -- 18 NOV 2005 1st Per. Q. Count the number of atoms of each element in one molecule of NaHCO3. A. (1) Na; (1) H; (1) C; (3) O 2nd-3rd Per. Q. Are you "actively participating in class" if the teacher must prompt you to pay attention and do your work? A. No! -- 29 NOV 2005 [Note: These PODs follow on the "Old Foamey" demo/graph.] 2nd-3rd Per. Q. A student collects time and temperature data. Which data set is the dependent variable? A. Temperature. [These data depend upon the outcome of the experiment.] Q. Which data set should go on the "X" axis of a graph? Explain. A. Time. By convention, the independent variable usually goes on the x-axis. -- 05 DEC 2005 Q. What is the name of the following substance? H-I-J-K-L-M-N-O A. H to O -- 14 DEC 2005 Q. The pH scale, numbered from 0-14, is logarithmic. A pH of 2 is how many times stronger than 5? A. 10 x 10 x 10 = 1,000x -- 04-05 JAN 2006 [re: lab activity, "Disappearing Powder - Investigating Solubility, Part 1: Creating and Interpretting Solubility Graphs," pp. 97-104] Q. If you were given a medicine cup filled with a "mystery powder," then what information would you need to know in order to determine how much of the powder was used during the experiment? A1. To find the initial mass of the powder, subtract the mass of the empty med. cup from the mass of the med. cup plus the powder. A2. To find the final mass of the powder, subtract the mass of the empty med. cup from the mass of the left-over powder. A3. To find the mass of powder used during the experiment, subtract the mass of the left-over powder from the initial mass of the powder. -- 06 JAN 2006 Q. For the following sets of numbers, what is the MEDIAN? Note: MEAN = average; MODE = most frequent no. A) 10, 2, 8, 5, 3 B) 7, 9, 1, 5, 11, 6 First, arrange the numbers in SERIES from smallest to largest: A) 2, 3, 5, 8, 10 B) 1, 5, 6, 7, 9, 11 The MEDIAN is the middle number: A) 5 B) 6.5 [MEAN (avg.) of the two middle numbers] -- 09 JAN 2006 Q. What is an ordered pair of numbers? A. ordered pair: Set of two numbers in which the order has an agreed-upon meaning, such as the Cartesian coordinates (x, y), where the first coordinate represents the horizontal position, and the second coordinate represents the vertical position. -- 10 JAN 2006 Q. [re: solubilty graph of KNO3] At the point(s) shown on the graph, would the solution be unsaturated or saturated? A. Answer varies: Point above the line, saturated; below the line, unsaturated. Calculate amount of surplus, or amount of deficit. -- 11-12 JAN 2006 Q. At a temperature of 60C, what is the mass of KNO3 required to saturate 100ml of water? (Refer to your "Gizmo" graph of Solubility and Temperature.) A. ~110g -- 13 JAN 2006 Q. In the following solutions, identify the solute and solvent: - Solution of 400g CuSO4 and 1000 ml of H2O A. CuSO4 = solute; H2O = solvent. - 1:3 solution of ammonia and water A. Ammonia = solute; water = solvent. -- 17 JAN 2006 Q. Refer to the graph on p. 103, Green Student Lab Guide. 40g of KNO3 is added to 100ml of H2O at 60dC -- is the resulting solution saturated or unsaturated? A. Unsaturated. At 60dC, it takes ~110g of KNO3 to saturate 100ml of H2O. -- 18 JAN 2006 Q. When a solute dissolves in a solvent, does a chemical- or physical change occur? A. A physical change. == YSLG ---- 26-27 JAN 2006 Q. There is no such thing as "cold" -- it simply does not exist! Explain why the preceding statement is true. A. There is only thermal energy, more or less thermal energy. In everyday language, we call less thermal energy "cold." 31 JAN 2006 Video POD: Physical Science, Vol. I: Videodisc Movie #69 - "Hot & Cold Dye" Listen to narration; answer question posed by narrator. Q. Can you tell which beaker is hot and cold? [Why?] A. The beaker on the left is hot; right cold. The dye disperses more rapidly in the hot water because it has more thermal energy (its molecules are moving faster). -- 01-02 FEB 2006 Compare/contrast two samples of water: (A) A cup of boiling water; (B) A lake at 20dC. Q. Which sample has the higher _temperature_? A. Cup of boiling water Q. Which sample contains more _thermal energy_? A. Lake at 20dC -- 03 FEB 2006 Q. Two vials [samples] of water are mixed; what is the water temperature after mixing? Vial [Sample] A = 100 ml @ 60dC; Vial [Sample] B = 100 ml at 10dC A. 6000C + 1000C / 200 = 35C -- 07 FEB 2006 Q. Two water samples are mixed; what is the temperature of the mixture? Sample A = 100 ml @ 50dC; Sample B = 10 ml @ 10dC A. 5000C + 100C / 110 = 46.4C Q. [Show graph, "Tracking the Heat - Contact"] What happened at this point (~11 min)? A. The hot & cold water reached thermal equilibrium. -- 10 FEB 2006 Q. When two substances reach thermal equilibrium, kinetic energy is still transferred between their molecules. Explain how it is possible for their temperatures to remain the same. A. Dynamic equilibrium. -- 15-16 FEB 2006 XMBL Replay Demo-PODs: Set up a 200-Watt lamp 20 cm from a black- and white flower pot. After x min., temps stabilize at ~34C (black) and ~30C (white). Q. How is energy transferred from the lamp to the flower pots? A. Radiation Q. Why haven't the temps changed for over an hour? A. Radiation balance (or radiative balance) Q. Trace the flow of energy from one form to another. List all of the "links" in the energy chain, that is, how energy is transferred & transformed. A. electrical energy to thermal energy to radiant energy (light), which is absorbed by the flower pots and transformed into thermal energy -- 17 FEB 2006 [follow-up on light sensor demo & ir wxsat activity] Q. Which color paper has the highest reflectivity? A. white Q. Which color paper has the lowest reflectivity? A. black Q. Do you think planet Earth has a high reflectivity? Why or why not? A. Some Earth surfaces have a high "albedo," such as sand, snow, water (when angle of incidence is low), and clouds. albedo: ratio of the amount of electromagnetic energy reflected by a surface to the amount of energy incident upon it tes.asu.edu/webdata/glossary.html -- 22-23 FEB 2006 Radiant energy from the Sun warms the Earth; the Earth re-radiates energy that warms the atmosphere. Q. What type of electromagnetic radiation does the Earth emit? A. infrared radiation Q. Why is the atmosphere heated less when the ground is snow-covered? A. Snow is white; white is more reflective. The Earth absorbs/re-radiates less radiant energy. -- 24 FEB 2006 Q. In the beaker (shown below), where is the least dense water? [Note: Beaker over candle flame, lower-left corner.] A. Lower-left corner, directly above candle flame. -- 27 FEB 2006 Q. Based upon what you know about density, explain how the Lava Lite(tm) works. A. Two liquids, similar densities, plus waxy substance. -- 03 FEB 2006 Q. Although the heat output of the hotplate was constant, the "Boiling Temperature of Water" graph shows two plateaus, each one indicating that the water temperature did not change for a period of time. Where did the thermal energy (heat) "go" during the times when the temperature did not change? Remember, the Law of Conservation of Mass & _Energy_ says we must be able to _account_ for _all_ of the energy added to the water! A. When temp increased, thermal energy (heat) was transformed into kinetic energy. During temp plateaus (associated with phase changes), thermal energy was transformed into potential energy. -- 06 MAR 2006 Q. In the beaker of _boiling water_ (shown left), what is inside the bubbles? A. Water vapor Q. What is the name of the phase change from liquid to solid? A. Freezing (seque to "Is Freezing Cold?" lab activity) 07 MAR 2006 Q. Refer to the graph of temp versus time for a beaker of warm _water_. What is indicated by the plateau beginning at the 10-minute mark? [Graph showing: temps from -10C to 40C (by 10s); times from 0 to 25 min (by 5s).] A. The water has reached thermal equilibrium with the air temp of the room. Point of Focus: Not all temp plateaus indicate a phase change is occuring! -- 08 MAR 2006 Q. What is the temperature at which water condenses? A. The dew point temperature. Point of Focus: The boiling point and condensation point of water are NOT the same! == PSLG ---- 22-23 MAR 2006 Q. Give an EXAMPLE of the following energy transformations: 1) nuclear to radiant to chemical 2) nuclear to radiant to chemical to electrical A. 1) nuclear fusion --> sunlight --> photosynthesis in plants 2) nuclear fusion --> sunlight --> photosynthesis in plants/lemon tree --> lemon chemical wet cell (battery) -- 27 MAR 2006 Q. Draw a lemon chemical wet cell. Label the essential parts of the lemon chemical wet cell. A. Container (lemon peel); electrolyte (lemon juice, citric acid); electrodes (different substances); conducting pathway (wire) closes the circuit. Q. You are designing an electric battery. Why is it important to use electrodes made of different substances (elements or compounds)? A. If the electrodes are the same, then there is no potential difference (voltage). -- 31 MAR 2006 Q. [write on blackboard...] Answer Ques. 3 shown on-screen (to left). [VA SOLs, Fixed Set No. 5, Ques. #3] Which of the following orientations of magnets would result in the _greatest_ attraction between the two magnets? A. F [A] Q. At which point (1-4) would the magnetic field be strongest? [2341] A. 1 -- 05-06 APR 2006 Prerequisite Info: Ohm's Law: I = V/r Where: I = current (amperage), amps (A) V = voltage r = resistance Q. Given a constant _voltage_, what is the mathematical relationship between _resistance_ & _current_? Q. Apply what you know (above) to explain what happens when you add more lights to a series circuit. -- [provide handout, PODs_re-Series-Parallel-Circuit.doc] Q. Series Circuit Given the positive & negative terminals on 9V battery, label the (+) and (-) terminals on the light bulb fixtures. A. connect unlike terminals (+,-,+,-, etc.) Q. Parallel Circuit "Rewire" the series of light fixtures so they are wired in parallel. Q. GWTF, Part 2 - Why isn't there a one-bulb parallel circuit? A. If there's only one bulb in the circuit, then it's a SERIES circuit! -- 21 APR 2006 [Show graphic featuring 5 crests w/in a 10 sec. bracket.] Q. What is the frequency of the wave shown above-left? A. 4 wavelengths/10 sec. = 0.4 waves/sec or Hz Note: Many students count number of crests, not number of wavelengths, resulting in the wrong answer. -- 24 APR 2006 [Show diagram of a transverse wave.] Q. What type of wave is shown? A. transverse Q. Label the parts of a wave: (1)rest position; (2)crest; (3)trough; (4)wavelength; (5)amplitude. -- 26 APR 2006 Q. What is the energy transformation that results in the transfer of energy from the Sun to the Earth? [Note: The "energy chain" has two (2) links.] A. nuclear energy (fusion) --> radiant energy -- 01 MAY 2006 [throw-back PODs] Q. What is the device inside the DuraPRO(R) flashlight (Costco) that makes it battery-free? A. a generator and a long-life rechargeable battery Q. Make an "energy chain" that shows the three (3) energy transformations. A. chemical --> mechanical --> electrical --> radiant chemical energy --> mechanical energy (kinetic) --> electrical energy --> radiant energy == RSLG ---- 09 MAY 2006 (Mo-PODs) Q. What is "ultrasound?" [throw-back POD] A. "Beyond" sound, that is, sound that is beyond the normal range of human hearing (20-20,000 Hz). Q. How does the motion detector use ultrasound to determine the distance to an object? A1. emit/receive. 1/2 travel time x speed of sound A2. We know the speed of sound (~343 m/s or ~750 miles/hour). Distance to target = travel time (TT), to & from target (s) * 343 m/s / 2 -- 10-11 MAY 2006 (Mo-PODs) Q. What is shown by a graph of distance vs. time? A. (Average) Speed avg speed (s) = total distance (d) / total time (t) HONORS: Q. If the speed of sound is 343 m/s, then what is the travel time to a target 3 m from the motion detector? A. 3m = TTs * 343m/s / 2 3m * 2 = TTs * 343m/s 3m * 2 / 343m/s = TTs TTs = 0.017 or 0.02 sec Per. 2,3: Q. Refer to RSLG, p. 5, Position Match 4. What is the average speed during the second line segment? A. 1 m / 3 sec = 0.333 m/sec -- 12 MAY 2006 Q. Refer to the following graph (showing acceleration): Distance-Match-2_modified_ver2.xmbl What is the _average speed_ for the 10-sec. time period shown by the graph? A. 0.2 m/sec, ~equal to mid-point of graph. *** NOTE *** For a RICH source of RSLG-related PODs, refer the following resource: http://www.wsanford.com/~wsanford/gr8ps/04_red/assessment/ RSLG_Test-Item-Bank.txt *** END NOTE *** -- 22 MAY 2006 "Gravity's Pull" Problem: Use overhead transparency master, "Newton Spring Scale" (T23) to test the spring scale "readability (metric)" in newtons. Q. What is the weight (N) of the object(s) shown on the overhead transparency? [Object A, B, C, etc.] <-- Note: In "Gravity's Pull," title of data table column = "Object" A. [answers will vary, e.g., 4.9 N] Q. What is the weight of a(n) 500-gram object? A. convert grams to kg (0.5 kg); multiply by 9.8 N (4.9 N) -- 30 MAY 2006 Q. What is shown by a graph of distance vs. time? A. Speed Q. What is shown by a graph of velocity (speed) vs. time? A. Acceleration -- 31 MAY 2006 Q. Look *carefully* at the graph you created yesterday (KoT, Avg Spd vs. Dist) -- does it *really* show acceleration? A. No! Avg Spd vs. Time shows acceleration!!! [demo 04_red/03_keep_on_truckin/KoT_Part2_v4a_analyzed.xmbl] Q. Problem(s) re: positive- & negative acceleration using formula: a = v(f) - v(i) / t A. ? -- 05 JUN 2006 P.O.D. Q. Which one of Newton's Three Laws of Motion is illustrated by the comic (shown left)? extras/bc0807g.gif A. Law 1 [inertia] -- 09 JUN 2006 Q. How much work is done to lift a 500-g mass 20 cm? (Hint: See "Work Made Easy" re: force required to lift a 500-g mass.) A. W = 5N x .2m or 1N-m or 1J Q. Given the formula for work, solve for _force_. What is the mathematical relationship between F & d? A. Given constant W, then F & d are inversely related. -- 12 JUN 2006 P.O.D.s (or "Bell WORK"): Q. What type of simple machine is a see-saw? A. Lever Q. When "playing" on a see-saw, how could a small child (on one side) lift a large adult (on the other side)? A. If the child sits on one end of the see-saw, then the adult must sit nearer the fulcrum of the lever (see-saw). [Test this idea: Hang one 500g mass on the F(e) end of the meter stick; wrap a rubber band around a meter stick and hang two 500g masses from the rubber band; move the rubber band back & forth in order to find the balance point.]