Warm Up: August 30, 2013

• Ally dropped a delicate glass vase 6 feet from the top of a ladder onto a concrete floor. The glass did not break. Why?

• The ladder was 7 feet tall.

Correct HW

1.3 Measurement

• SI System (Systeme International d’Unites) is an international system of units used by scientists.

• It allows scientists in different countries to easily share data and results.

Length

• A measure of the distance between two points

• SI unit: meter (m)

• Instruments used : ruler, meter stick, measuring tape

Time

• A measure of the passing of events

• SI unit: second (s)

• Instruments used : clock, timer

Temperature

• A measure of the movement of molecules

• SI unit: Kelvin (K) (not °F or °C)

• Instrument used: thermometer

Volume

• A measure of the amount of space something takes up

• SI unit: Liter (L)

• Instrument used: graduated cylinder

Mass

• The amount of matter present

• SI unit: kilogram (kg) (1 kg = 1000 g)

A gram is approximately the mass of a paper clip.

Instrument: triple beam balance, digital balance

Weight • Weight is not the same as mass.

• Weight is force, or push or pull.

• Weight depends on gravity and depends on where you are in the universe.

• The units for weight are pounds (lb) or Newtons (N).

• Instrument: scale, spring scale

Measuring Volume

• We measure volume using a graduated cylinder.

• They come in a variety of sizes and materials (glass, plastic).

• The ones we use measure volume in milliliters (1000 mL = 1 L)

The Meniscus

• Many liquids, when placed in a graduated cylinder, will cling to the sides creating a u-shape called a meniscus.

• You always use the BOTTOM of the meniscus to make a measurement.

Rainbow Lab

• In this lab you will practice using a graduated cylinder to measure volume.

• Everyone at your table must make at least one measurement with the graduated cylinder.

• Label 6 test tubes in order: A, B, C, D, E & F.

• Into test tube A, measure 25 mL of RED liquid. • Into test tube C, measure 17 mL of YELLOW liquid. • Into test tube E, measure 21 mL of BLUE liquid.

• Part 2:• From test tube C, measure 4 mL and pour into test tube D. • From test tube E, measure 7 mL and pour into test tube D. Swirl. • From test tube E, measure 4 mL and pour into test tube F. • From test tube A, measure 7 mL and pour into test tube F. Swirl. • From test tube A, measure 8 mL and pour into test tube B. • From test tube C, measure 3 mL and pour into test tube B. Swirl.

Things to think about…1. Is there any water or food coloring on your hands

or the table? If this liquid was hydrochloric acid, you lost some of your data and may have burned yourself!

2. Are the volumes in the test tubes what they should be at the end? Double check!

Example: Test tube A should have 25 - 7 - 8 = 10 mL Pour the contents on A back in the graduated cylinder and see how you did.

Homework

• P. 26 #1a-b & #2a-c• 1.3 Vocabulary Booklet Part I – define: SI,

weight, mass, volume, meniscus, density (6 words on p. 16)