Aim: What is Density?

Do Now:

In your notebooks, describe how to find the density of an object (formula).

Also, what do you think determines an objects density?

I. Density: The amount of matter in a specific volume

- A physical property of matter.

- Measured in g/cm3 or g/ml.

- Helps identify matter. Every object has a different density.

D = MV

** Density of an object remains the same no

matter how many pieces it’s broken into

**

Using the one density formula you can rearrange the variables to solve for

mass and volume.

DensityMass

Volume=Density

Mass =

Density x

Volume

MassVolume=Density

D

M

V

II. Buoyancy vs. Density

• Buoyancy is an objects ability to float in water.

- determines if an object will sink, float or remain neutral in water.

What does neutrally buoyant look like?

• Which color liquid is most dense?

• Which color liquid is least dense?

• Where would a metal sphere with a density of 3.0g/ml land?

5.4 g/ml -

4.3 g/ml -

2.9 g/ml -

1.3 g/ml -

Example: Compare the density of H2O (water) to the density of an ice cube.

THINKAn ice cube floats in H2O because

it has a density:a) Equal to the density of waterb) Greater than the density of waterc) Less than the density of waterd) None of the above

Why does a steel ship float in water?

Densities in grams / cm3D (water) = 1.0 g / cm3D (wood) = 0.8 g / cm3D (steel) = 7.8 g / cm3D (lead) 11.3 g / cm3D (air) .0012 g / cm3Answer:

A ship has a steel shell that is hollow inside. The volume is mostly air. The ship and air together have a density less

than water.

• Closure:

From the back table, top bin; take a density review worksheet from the top bin to work on in class with your partner.