State the Problem

Lab:DENSITY Name

CHANGEABLE OR UNCHANGEABLE?Hour

STATE THE PROBLEM:

Does the density of a substance change or does it remain the same as pieces are cut off of it?

COLLECT INFO:

What is the unit of mass? unit of volume? unit of density?

Define:

Qualitative Data –

Quantitative Data -

When you tear a piece of paper in half it is still paper. If you drink part of a can of Mt. Dew, there is still

Mt. Dew left in the pop can. If you break off and eat a piece of a KitKat bar there is still KitKat bar left.

Density is a measure of how closely or loosely packed the particles are in a substance. Remember that errors occur in every measurement we make. The candy bars are not completely regularly shaped. Keep in mind that your volume will be a little “off.” So, be a critical thinker when coming to a conclusion for this lab activity.

HYPOTHESIS

Will the density of your candy bar change or will the density remain the same as you cut pieces off of it?

Safety tip:

Because we often work with non-edible chemicals in this class, please do not ever set your candy bar directly onto the tray of the triple beam balance or the table. Always put your candy bar on a piece of paper before setting it on top of the triple beam balance or the table.

TEST IT

1.Unwrap your candy bar--do not eat it! (The eating part will come later.)

2.Measure the mass of your candy bar. Record on your data table.

3.Measure the volume of your candy bar. Record on your data table.

4.Calculate the density of your candy bar. Record on your data table.

5.Cut off a small part of your candy bar. You will need to take five bites all together so don't cut bites that are too huge. Eat only the small part you cut off.

6.Repeat steps 2 through 4 with the remaining part of your candy bar.

7.Continue this process of cutting and eating pieces of your candy bar and recalculating density until you have completely filled your data table.

Data Table: Be sure to include all units

TRIAL # MASS VOLUMEDENSITY

CONCLUSIONS: Please use complete sentences for full credit.

1.List 4 uncertainties that occurred during this lab activity and explain your answers. (Things that could have affected the accuracy of your measurements)

2.What happened to the mass as you cut off parts of your candy bar?

3.What happened to the volume as you cut off parts of your candy bar?

4.What happened to the density as you cut off parts of your candy bar?

5.Does the size of your candy bar affect its density? Why or why not?

6.Is density a qualitative or a quantitative property? Explain your choice.

7.Compare the density of your candy bar to the density of other groups' bars. Are they similar?

Why or why not?

8.Give specific reasons why it would be difficult to find the density of the following substances.

a.Salted Nut Roll

b.Almond Joy

c.Apple

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