Chemistry Honors – Class 02

Sig Figs Rule!

Dates

• Periods B: Tuesday, August 27th
• Periods D, G: Wednesday, August 28th

Measurement

• from yesterday – examine different numbers recorded for volume
• measurement = comparison to a standard
• depends on user and device
• no such thing as pure truth
• (in Math numbers are IDEAS)
• users and devices introduce uncertainty
• written number expresses uncertainty
• Significant Figures – certain digits plus good guess

Activity Revisited

• fill 100 mL beaker half way (approximately) and measure the volume
• repeat for the two different graduated cylinders (10 mL, 50 mL)
• Note – meniscus = bottom of liquid
• record the air temperature using the thermometer
• measure the width of the table (use the side marked in cm)
• create a table to organize your information – label properly
• include proper units
• be ready to share with the class

Homework

• Read – take notes on Ch. 1.3 -1.4
• Typed notes to PDF  in shared folder
• ONE MORE THING – please buy lab notebook ASAP LINK = http://goo.gl/nf28RW