AGENDA 24-SEPT:  Please find your seat!  CW – PJAS Critique Homework  Finish PJAS Critique write- up and Essay  PJAS #2 due tomorrow!

PJAS Critique  Make a rough draft of Tasks #1-4 (5 if time)  FINAL COPY MUST BE WRITTEN IN INK ON GRAPHING PAPER (per student) –Name/Date –Title –Hypothesis –Design Diagram –Materials –Procedure –Data (table and space for graph) –Essay

Examples of testable, non-fact hypotheses  If a ball has a greater amount of pressure (lbs/in 2 ), then it will bounce higher when dropped from a fixed height.

Examples of testable, non-fact hypotheses  If you take different colors of light and shine them at an object then the objects will become different temperatures.

Examples of testable, non-fact hypotheses  If the temperature of Gatorade increases, then the conductivity will also increase.

AGENDA 25-SEPT:  Turn/Review in PJAS Critique  Notes – Scientific Measurement Homework Think about PJAS #3

Scientific Measurement Mrs. Falatek

Definition Comparison to a standard

Metric System  Based on units of 10  Used internationally and always in science  Base Units: –Meter = length –Liter = volume –Gram = mass –Kelvin = temperature –Ampere = current

Measuring Distance... Length Length –Distance between two points.

Measuring Volume... Volume Volume –amount of space occupied by an object. –The volume of a two dimensional, rectangular object = length times its width. –The volume of a three dimensional rectangular object = length times width times height. 1 mL = 1 cm 3

Measuring Volume... Volume Volume –The volume of an irregularly shaped object is calculated by VOLUME DISPLACEMENT! –See drawing on board.

Measuring Temperature... Temperature Temperature –is a measure of how much energy a substance has. –The SI unit for temperature is Kelvin, K. Other common units for temperature are (ask class for examples) Celsius, C, and Fahrenheit, F.

Prefixes  Each prefix represents a number (a multiple of 10) that indicates the size of the measurement MegaKiloHectoDeca Base UnitDeciCentiMilliMicroNanoPico (M)(k)(h)(da) Gram (g) Meter (m) (d)c(m)  (n)(p) Liter (L) /101/1001/10001/ /1x10 9 one billionth 1/1x10 12 one trillionth

Prefixes Example:  Kilo means 1000  Milli means 1/ Convert 1 gram to kilograms: move decimal THREE places to the LEFT (0.001 kg) 2.Convert 1 gram to milligrams: move decimal THREE places to the RIGHT (1000 mg)

Prefixes cm Size What

Metric Estimations What metric unit would you use to describe the following? 1.The distance from the earth to the moon 2.The contents of a one gallon milk jug 3.Your weight 4.The length of an eyelash 5.The amount of soda in a can

AGENDA 26-SEPT:  Factor Label Method of converting  CW – conversions mega sheet Homework  Conversions Mega Sheet  PJAS #3 due Friday!

The Factor Label Method A method of converting between one quantity and another. A method of converting between one quantity and another. Conversion factor – describes the relationship between two units (1 mm = 1000  m) Conversion factor – describes the relationship between two units (1 mm = 1000  m) 4.5 m 1000 mm = _____ mm 1m. 1m.

The Factor Label Method Let’s complete #1-3 on your worksheet: Let’s complete #1-3 on your worksheet: #1) #1) #2) #2) #3) #3)

The Factor Label Method Try this: Try this: The directions for an experiment ask each student to measure 1.84 g of copper wire. The only copper wire available is a spool with a mass of 50.0 g. How many students can do the experiment before the copper runs out? The directions for an experiment ask each student to measure 1.84 g of copper wire. The only copper wire available is a spool with a mass of 50.0 g. How many students can do the experiment before the copper runs out?

The Factor Label Method Try this: Try this: An experiment requires that each student use an 8.5 cm length of magnesium ribbon. How many students can do the experiment if there is 570 cm of magnesium ribbon available? An experiment requires that each student use an 8.5 cm length of magnesium ribbon. How many students can do the experiment if there is 570 cm of magnesium ribbon available?

The Factor Label Method Let’s complete the calorie problem on the back of your worksheet: Let’s complete the calorie problem on the back of your worksheet: How many calories are there is 4 tsp of sugar? How many calories are there is 4 tsp of sugar?

The Factor Label Method Try these: Try these: Convert 8 hr to seconds. Convert 8 hr to seconds. How many minutes are there in one week? How many minutes are there in one week?

AGENDA 29-SEPT:  Submit work from conversions mega sheet  CW – finish HW side of conversions mega sheet  Measurement Pre- lab Homework  Part 1 – Measurement Lab  PJAS #3 due Friday!

AGENDA 1/2-OCT:  Check Part 1  Measurement Pre-Lab  Measurement Lab Homework  Part 2 – Measurement Lab  TEST NEXT WEDNESDAY

Measurement Lab. Modify procedure: Activity 2, Part III – use a 50 mL graduated cylinder instead of a 100 mL. Modify procedure: Activity 2, Part III – use a 50 mL graduated cylinder instead of a 100 mL. Materials are located against the walls around the room. DESIGNATE ONE PERSON TO COLLECT MATERIALS PER GROUP/PER ACTIVITY. Materials are located against the walls around the room. DESIGNATE ONE PERSON TO COLLECT MATERIALS PER GROUP/PER ACTIVITY.

Measurement Lab Write-up Procedure: … Data & Conclusion: Activity 1 Activity 1 Data table 1&2 Data table 1&2 Activity 2 Activity 2 Part I, II & Data table, III Part I, II & Data table, III Activity 3 Activity 3 Part 1 & PL question, II Data table & PL questions, IV Part 1 & PL question, II Data table & PL questions, IV Activity 4 Activity 4 Data table and PL questions Data table and PL questions

Pre-Class:  1 meter is equivalent to ft. Convert 1.25 meters to feet using the correct conversion factor!  How would measure the volume of an irregularly shaped object?  You data is a measure of change in temperature over time. Which type of graph would you use to represent your data?

AGENDA 3-OCT:  Pre-Class  Submit Measurement Lab  Notes – Density and Sig Figs  CW – Density & Sig Figs Practice Homework  Test Wednesday  Measurement Review WS

Density is an INTENSIVE property. Density depends only on the composition of a substance, not on the size of the sample. Density depends only on the composition of a substance, not on the size of the sample. Is defined as mass per unit volume. Is defined as mass per unit volume. Is calculated by dividing mass by volume. Units are g/ml or g/cm 3. Is calculated by dividing mass by volume. Units are g/ml or g/cm 3.

Calculating Density Let’s try these: Let’s try these: A copper penny has a mass of 3.1 g and a volume of 0.35 cm 3. What is the density of copper? A copper penny has a mass of 3.1 g and a volume of 0.35 cm 3. What is the density of copper? A bar of silver has a mass of 68.0 g and a volume of 6.48 cm 3. What is the density of silver? A bar of silver has a mass of 68.0 g and a volume of 6.48 cm 3. What is the density of silver?

How do we measure density? Measure the area of a REGULARLY SHAPED object to get its density Measure the area of a REGULARLY SHAPED object to get its density Water displacement for IRREGULARLY SHAPED objects (like a rock) Water displacement for IRREGULARLY SHAPED objects (like a rock)

AGENDA 6-OCT:  Submit Measurement Review WS  Notes – Sig Figs  CW – Sig Figs Practice Homework  Test Monday 10/13

Significant Figures Refers to the digits of a number of which we are CERTAIN (no one would argue with us) plus Refers to the digits of a number of which we are CERTAIN (no one would argue with us) plus ONLY ONE of which we are UNCERTAIN (we each might have a different digit as the final digit) ONLY ONE of which we are UNCERTAIN (we each might have a different digit as the final digit)

Rules for Sig Figs  SIGNIFICANT 1.All non-zero numbers (1 through 9) 2.All “trapped” zeros 3.END and AFTER = at the end of a number AND after the decimal  NOT SIGNIFICANT 1.Place holder zeros

Counting sig figs  IT’S THE ZEROS THAT ARE TRICKY!!  How many sig figs here:

Significant Figures Multiplying & dividing- answers must contain the same number of significant figures as in the number that has the least amount of significant figures Adding & subtracting - answers must contain the same number of digits as in the number with the greatest uncertainty (least number of decimal places)

AGENDA 7-OCT:  Submit Homework  Notes – Scientific Notation  CW – Scientific Notation Practice & Accuracy/Precision WS Homework  Scientific Notation WS  Test MONDAY 10/13

Scientific Notation  Shorthand number writing  g = 4.59 x g

4.59 x g = must be between 1 and = always base = tells if original number is less than one (-) or greater than one (+) AND direction you moved decimal 4. 7 = how many places decimal moved

Try these  x  23,000, x 10 7  x 10 2  x 10 -3

Confusing Words in Science  Accurate – a measure of how close a measurement comes to the actual value of whatever is measure.  Precise – a measure of how close a series of measurements are to one another.

Confusing Words in Science In my own words…  Accurate = you’re right!  Precise = a bunch of numbers are close together

Accuracy and Precision  Accurate = you’re right!  Precise = a bunch of numbers are close together

Accuracy and Precision To evaluate accuracy, you must compare your value to the correct value!  Error = experimental value – accepted value  % Error = (error ÷ accepted value) x 100

Calculating Error During an experiment, I found the boiling point of pure water to be 98°C, however we all know the accepted value to be 100°C. Calculate the percent error in my measurement.  Error = 98°C – 100°C  % Error = (2°C ÷ 100°C) x 100 = 2%