15 Sept. 2010 Homework: Background info paragraph Objective: SWBAT make and record accurate measurements using scientific equipment. Do now: Name a piece of equipment used to measure mass, two that measure volume, and one that measures length. SWBAT make and record accurate measurements using scientific equipment.

Agenda Do now Making measurements stations Discussion Notes on science equipment SWBAT make and record accurate measurements using scientific equipment.

Making measurements stations Record all your data on your lined paper. Be sure to label what it is. Ex: Station 1 Mass of block: 45.73 g SWBAT make and record accurate measurements using scientific equipment.

Making Measurements in Chemistry

Length: Meter Stick Units: centimeters (cm), meters (m) SWBAT make and record accurate measurements using scientific equipment.

Mass: Electronic Balance Grams (g), kilograms (kg) SWBAT make and record accurate measurements using scientific equipment.

Mass: Triple Beam Balance Grams (g), kilograms (kg) SWBAT make and record accurate measurements using scientific equipment.

Volume Liters (L), milliliters (mL) cubic centimeters (cm3) (“100 cc’s of saline, STAT!”) Volume

Beaker SWBAT make and record accurate measurements using scientific equipment.

Graduated Cylinder SWBAT make and record accurate measurements using scientific equipment.

Burette SWBAT make and record accurate measurements using scientific equipment.

Graduations: lines on lab equipment for measuring volume. SWBAT make and record accurate measurements using scientific equipment.

Meniscus Read the volume at the BOTTOM of the curve! Caused by surface tension of liquids (esp. water) SWBAT make and record accurate measurements using scientific equipment.

Meniscus SWBAT make and record accurate measurements using scientific equipment.

Temperature: Thermometer Degrees Celsius oC SWBAT make and record accurate measurements using scientific equipment.

Graduated Cylinder Beaker Burette Least Accurate Most Accurate Test tube Graduated Cylinder Beaker Burette Fewest Graduations Most Graduations SWBAT make and record accurate measurements using scientific equipment.

When reading a piece of equipment, you can “guess” the last digit. SWBAT make and record accurate measurements using scientific equipment.

Uncertainties in Measurements

Uncertainties: ± (“plus or minus”) a range of values in which your measurement falls These do not affect your results Ex: Your graduated cylinder is accurate to ±0.05 mL (could be up to 0.05 mL too high or too low!) SWBAT make and record accurate measurements using scientific equipment.

Graduated Cylinder Beaker Burette Least Accurate Most Accurate 10 mL 1 mL 0.1 mL Test tube Graduated Cylinder Beaker Burette Fewest Graduations Most Graduations SWBAT make and record accurate measurements using scientific equipment.

Uncertainty = ± half of the smallest graduation Uncertainties: ± (“plus or minus”) a range of values in which your measurement falls These do not affect your results Ex: Your graduated cylinder is accurate to ±0.05 mL (could be up to 0.05 mL too high or too low!) Uncertainty = ± half of the smallest graduation SWBAT make and record accurate measurements using scientific equipment.

36.5 ± 0. 5 mL Uncertainty SWBAT make and record accurate measurements using scientific equipment.

52.9 ± 0.5 mL SWBAT make and record accurate measurements using scientific equipment.

SWBAT make and record accurate measurements using scientific equipment.

SWBAT make and record accurate measurements using scientific equipment.

27.5 ± 0.5 mL SWBAT make and record accurate measurements using scientific equipment.

SWBAT make and record accurate measurements using scientific equipment.

40.05 ± 0.05 mL SWBAT make and record accurate measurements using scientific equipment.

SWBAT make and record accurate measurements using scientific equipment.

SWBAT make and record accurate measurements using scientific equipment.

cm SWBAT make and record accurate measurements using scientific equipment.

Which is the most accurate? Why? SWBAT make and record accurate measurements using scientific equipment.

What is the volume in this graduated cylinder (in mL)? What is the uncertainty? What equipment could you use to find a more accurate measurement for this volume? Do you think this graduated cylinder is accurate? Why or why not? If I read volumes of 8.11, 8.12, and 8.10 mL from this picture, would my answer be accurate, precise, both, or neither? Explain your answer. SWBAT make and record accurate measurements using scientific equipment.

Homework: Read Density of Pennies lab; reading quiz Tues. Tomorrow: Clickers! and brainstorming background info section for lab report. Homework: Read Density of Pennies lab; reading quiz Tues. SWBAT make and record accurate measurements using scientific equipment.