Student Name:___________________________________ 1) Scientific Method practice # 1 1) Use your imagination or examples from everyday life to come up with a problem and then use scientific method model to solve it. 1) Problem _______________________________________________________________ _____________________________________________________________ 2) Hypothesis( use: if , then, because statement) _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 3) Experiments/Data Control__________________________________________________________ _______________________________________________________________ Variable_________________________________________________________ _______________________________________________________________ _______________________________________________________________ 4) Conclusion________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ 1 Student Name:___________________________________ 2) Measurement practice #2 1) For each of the following, please state what place a measurement must be made to given the calibration points on a measuring device: If a device is marked to the Then estimate your nearest… answer to the nearest… Hundredth Ten Tenth Hundred 2) For each of the following, record the measurement, the number of significant figures and the precision of the measurement. Use the appropriate units. Examples Calibration Precision Reading (measurements) # of Sig Figs in the reading 2 3) For each of the following numbers, determine) how many significant figures are in the measurement. Measurement # SF Measurement 2347 cm 12556 cm 4 23405 kg 34.780 mL 63.908 mg 56.0600 mm 3400. cm 560 km 9700 mL 37000 kJ 0.00023 dg 0.000230 dg 1.00230 dg 34.000 cL # SF NOTE Significant figures are used for measurements only. Any zero that is not "Significant" is still there as a place holder. _ EXAMPLE: 560000 <- place-holding zeroes in the tenths and units place 3 Student Name:___________________________________ Grades: _____, _____, _____, _____, _____, _____ 3) Rounding practice # 3 Be sure to consider the number of significant figures in each of the following problems. For this exercise, consider all numbers to be measurements. Include the units in your answers. Write the UNROUNDED answer first, then the ROUNDED answer, drawing a box around your rounded answer. B) ADDITION Problem Unrounded Answer Rounded Answer, with units Unrounded Answer Rounded Answer, with units Unrounded Answer Rounded Answer, with units 4.732 cm + 16.8 cm + 0.781 cm 32.0 MW + 0.0059 MW C) SUBTRACTION Problem 22.95 mg – 6.4 mg 33.728 cL – 1.323 cL D) MULTIPLICATION/DIVISION Problem 37.66 KW X 2.2 h = 14.922 cm X 2.0 cm = 98.11 kg X 200 m = 19.82 g / 24.2 km = 4 F) OK, here is a practical problem in which you will combine all of your skills. The equation you will use is D = m/v (density = mass / volume). Remember to show a proper numerical setup (with units) and solve, making sure your final answer is properly rounded for the type of math you did: 1) A ring, supposedly made of pure silver (Ag) has a mass of 20.445 grams. When its volume is taken by water displacement, it is found to have a volume of 1.95 mL. Calculate the density of the ring: 2) Based on the actual density of silver (Ag) found on Reference Table S, could this ring actually be made out of silver? Briefly explain your answer: 5 Student Name:___________________________________ 4) Scientific Notation practice # 4 A) Convert each of the following into scientific notation: Number 250. Scientific Notation 1000 200 000 2100. 0.010 0.000 55 0.0070 0.0205 0.000 000 000 000 000 000 160 B) Convert each of the following into standard decimal notation: Scientific Notation 3.56 X 103 7.982 X 1011 8.3400 X 1015 7.02 X 10-4 6.6 X 1034 Standard Decimal Notation C) Ksp is a measurement of the solubility of a salt. The larger the value of Ksp is, the more salt can dissolve in water. Which of the following Ksp values(on the bottom of the page) would indicate the salt with the highest solubility? Provide your answer here____________________________________________ Which of the following Ksp values(on the bottom of the page) would indicate the salt with the lowest solubility? Provide your answer here____________________________________________ Given values a) 4.3 X 10-6 b) 5.7 X 10-7 c) 9.8 X 10-8 d) 3.2 x 10-9 6 Student Name:___________________________________ Grades: _____, _____, _____, _____, _____, _____ 5) Conversion practice # 5 A) Perform the following conversions, showing all work and units. For the first one, I give you places to fill in the preliminary information. For the rest, provide it yourself: 1) A black widow spider is found to have a mass of 0.90 grams. How many kg does this spider weigh? Conversion Factor:___________________________ 2) A friend of yours just drank 1460 milliliters of water. How many L of water is this? Conversion Factor:_____________________________________ 3) How many millimeters would you have run if you ran 0.8051 kilometers? Conversion Factor:________________________________________ 4) A snail is observed to move 8.32 cm in one minute. How many mm did the snail travel? Conversion Factor:________________________________ 5) The atomic radius of an atom is 37 pm. How many meters is that? Conversion Factor:_____________________________________ 6) The average weight of a 16th year old is 50 kilograms how many milligrams is this? 7) The time machine needs 1.21 Giga ( 109 ) watt of power to travel through time. How many centiwatts of power is that? 7 8