Section 2: Standards of Measurement

Chapter 1: The Nature of Science

Learning GoalsName the prefixes used in SI and indicate what multiple of ten each one represents.

Identify SI units and symbols.Convert related SI units.

Units and StandardsStandard: exact quantity that

people agree to use for comparison.

Measurement Systems Imperial system of measurement

Feet Pounds Gallons

Only 3 countries do not use the metric system of measurement: U.S.A., Myanmar, and Liberia

Measurement SystemsInternational System of Units (SI): an improved version of the metric system. Understood by scientists

worldwide Based on multiples of 10 and uses

prefixes to indicate a specific multiple.

Measurement Systems SI Base Units:

Length – meters (m) Mass – grams (g) Liquid volume – liters (L) Time – seconds (s)

Measurement Systems SI Prefixes:

Kilo (k) – x1000 Centi (c) – x 0.01 or 1/100 Milli (m) – x 0.001 or 1/1000

See the “Metric Toolbox” or Page 15 of your textbook for more

Measurement SystemsConverting between SI Units: Use conversion factors: ▪ ratios that are used to change one

unit to another

ExampleThere are 1000 mL in 1 L. How many mL are in 3 L?

Factor Label Method1. Write what you know on the left2. Write what you want on the right3. Put a conversion factor in the middle4. Cancel units on top and bottom5. Multiply top and divide bottom

ExampleThere are 100 cm in 1 m. How many cm are in 2.75 m?

ExampleHow long, in centimeters, is a

3,075 mm rope?

Let’s Practice!

Measuring DistanceLength is measured using a unit appropriate for the distance between two points.

Measuring DistanceThe SI unit of length is the meter (m).

cm

mm

Measuring VolumeVolume: the amount of space an object occupies.

The base unit for liquid volume is liters (L) Beakers, flasks, and graduated cylinders (mL)

Measuring VolumeMeasuring solid volumes:

Formulas: (V = l x w x h)▪Units in cubic centimeters (cm3) or cubic meters (m3)

Water displacement

Measuring MatterMass: a measurement of the quantity of matter in an object.

Base unit is grams (g)Balances can be used to measure mass

Measuring MatterDensity: the mass per unit volume

of a material. How much mass an object has in a

certain amount of space. Density = mass/volume Unit for density is grams per milliliter

(g/mL)

Measuring Time and Temperature

SI unit of time = seconds (s)Metric unit of temperature = degrees Celsius (°C)

SI unit of temperature = Kelvin (K)