SCIENTIFIC MEASUREMENTS

CHAPTER 2

UNIT OBJECTIVES: Students will:• Review metric measurements•Demonstrate proper metric measurement

techniques• Investigate ingredient content and affect of

ingredients on chewing gum

USING MEASUREMENTS

Accurate measurements must be taken to have a successful experiment.

The student must identify a system of measurements to be used.Metric versus Standard

Determine what you are trying to measure.Mass – the amount of matter in an object.Length – distance between two pointsVolume – amount of space occupied by an object

Determine which method will give you the most accurate results.

MEASUREMENT SYSTEMS•System International, SI units, Metric system

STANDARD SYSTEM

TYPE NAME SYMBOL

Mass Gram G

Length Meter M

Volume Liter L

Time Second S

Temperature Celsius degree ‘C

TYPE NAME SYMBOL EQUIPMENT USED

Mass Pounds, ounces lb, #, oz, Dry measuring cups

Length Inches, feet, miles In, ft, mi Ruler

Volume Fluid ounces, cup, pint, quart, gallon

fl. oz, c, pt, qt, gal

Liquid measuring cups

Time Second, minute, hour s, min., hr. Clock

Temperature Fahrenheit degree ‘F thermometer

•Mass-the amount of matter in an object•Will often have to use a container

(Use something light weight)•Use digital scales•Must subtract the weight of the container (taring)

or zeroing the scale. •Mass the container, then mass the substance and the

container. Subtract the mass of the container to find out the mass of the substance.

HOW TO MEASURE MASS

How to Measure Length

• Length-the distance between two pointsUse a ruler

• Place an object between two vertical surfaces, notate the location of the ends of the object and measure between the end points.

How to Measure Volume

• Volume-the amount of space occupied by an object

• Cube (l x w x h)• Liquids measured by volume (ounces, liters)• Measure liquids in clear containers with

graduated scales– Measure to the bottom of the meniscus (the curve

at the surface of the liquid)

How to Measure Time

You may use one of the following:• a second hand timer on a watch• the clock • The stove minute timer• or ask the teacher to use your cell phone.

How to Measure Temperature

• SI unit (metric) is Celsius notated ‘C, (Most recipes use Fahrenheit degrees, ‘F.)(Stoves measure in Fahrenheit degrees, ‘F.)

• Celsius – 0’C is freezing and 100’C is boiling• Fahrenheit – 32’F is freezing and 212’F is the

boiling point• C’ = (5/9) x (degree F’ – 32)

CHEWING GUM LAB IS NEXT

EXPERIMENT 2A - BALANCING CHEWING GUM

OBJECTIVE:Scientific procedures require accuracy and consistency. The student will :become familiar with the electronic balance (scale) and how to use it. EQUIPMENT:Electronic balance (scale)1- stick regular chewing gum per lab member1-stick sugar-free chewing gum per lab member

PRE-LAB and POST LABCopy each of the questions that follow and prepare the charts as directed. Read each question and in the left column predict the results. In the right column, record your data and findings. PROCEDURE:1. Become familiar with the electronic scale 2. Use the gum wrapper as weighing paper. Tare (weigh) the gum wrapper.3. Mass the regular gum. Record the mass in the data table (see example below).

4. Chew the gum for TWO minutes. (Watch the clock closely for accuracy.)

5. Place the chewed gum on the weighing paper and mass it. Record the mass in your data table.

6. Subtract the mass of the chewed gum from the original mass of the gum and record the difference.

7. Repeat the above procedures with the sugar-free gum. Record all your data in the chart. QUESTIONS: 1. Which type of gum will have a greater loss of mass after chewing?

2. Will there be a difference in texture between the two types of gum? If so, describe it?

3. What substance causes the loss of mass and difference of texture during chewing?

4. Given that sugar has 4 calories per gram, how many calories would you estimate are in a stick of gum?

5. How does your answer compare to the nutrition label on the gum package?

6. What substance might cause the gain or loss of mass after chewing?

LAB DATA:Tare of the gum wrapper:

GUM TYPE MASS BEFORE

CHEWING

MASS AFTER CHEWING

MASS LOST/GAINED

REGULAR GUM

SUGAR-FREE GUM

SUGAR-FREE GUM REGULAR GUM

Sorbital, gum base, glycerol, mannitol, natural and artificial flavors, hydrogenated starch hydrolysate, less than 2% of aspartame, acesulfame K, soy lecithin, BHT (to maintain freshness), colors (turmeric, blue 1 lake). Pheylketonurics, contains phenylalanine.

Sugar, gum base, dextrose, corn syrups, natural and artificial flavors, less than 2% of glycerol, aspartame, gum arabic, soy lecithin, acesulfame K, color (titanium dioxide, blue 1 lake, beta-carotene), BHT (to maintain freshness). Pheylketonurics, contains phenylalanine.

LIST OF INGREDIENTS

SUGAR-FREE GUM REGULAR GUM

Serving Size: 1 stick (2.7 g)Amount per servingCalories 5Total Fat 0 gSodium 0 gTotal Carbohydrate 2 gSugars 2 gSugar Alcohol 2 g Protein 0 g

Serving Size: 1 stick (2.7 g)Amount per servingCalories 10Total Fat 0 gSodium 0 gTotal Carbohydrate 2 gSugars 2 gProtein 0 g

NUTRITION FACTS

CONCLUSION

• An interpretation of the data using graphs, charts, or paragraphs.

• Explains the data collected.• Uses words like: ‘since’, ‘because’, ‘the reason

I know this is . . .’• Points out supporting or opposing facts.• May explain problems encountered during the

experiment.

GUM EXPERIMENT CONCLUSION

• Make a one or two sentence statement relating your predictions, your facts and your conclusions from the experiment.