1. A Characteristic Property of Matter
Density
A Characteristic Property of Matter

2. Density Density is a basic characteristic property of all matter
A characteristic property is a property that stays the same for a particular type of matter. For instance: H2O boils at 100 oC and freezes at 0 oC
Every substance has a density that can be measured
Scientists use density to help identify different kinds of matter

3. Formula for calculating density
Density is mass per unit of volume
Density is mass divided by volume
D =

4. Unit for Density g/ml or g/cm3 Mass is measured in grams
Volume is measured in
ml or cm3
Therefore, the unit for density is
g/ml or
g/cm3

5. How Do We Measure mass?
Scientists use a triple beam balance to measure mass.
What is the mass illustrated on the triple beam balance?

6. How do we measure volume?
How would you use to measure the volume of a regularly shaped object, such as a box?
Which one is the meter
stick?
V = l x w x h
How would you use to measure the volume an irregularly shaped object, such as a rock?

7. WATER DISPLACEMENT METHOD
You Have Choices!
Both choices involve water
Both choices move water out of the way to make room for the object
To move something out of the way to make room for something else is called DISPLACEMENT
Therefore, this method is referred to as the
WATER DISPLACEMENT METHOD

8. But First, let’s review how to read the volume of a fluid
Does the word meniscus ring a bell?
Meniscus: the curvature of a liquid in a tube
Most liquids curve down, some curve up
If the liquid curves down, you measure the bottom of the curve
If the liquid curves up, you measure the top of the curve
What is the volume of the H2O and the Hg (mercury)?

9. The Proper Way to Measure
Eye Level!

10. OK, back to the choices!
Method #1: Place object in graduated cylinder and read the increase in volume.
Method #2: Place the object in an overflow can and measure the amount of water displaced.

11. Question How would you measure the MASS of a liquid?
What must you remember to do first?

12. Now you can calculate density
You can measure the mass of the object
You can measure the volume of the object
Divide the mass of the object by it’s volume and
you have calculated the density

13. Minds on Science Obtain 2 different size graduated cylinders
Fill each cylinder about half full with H2O
Determine mass and volume of the H2O in each cylinder
Calculate the density of the water in cylinder #1
Calculate the density of the water in cylinder #2
What did you find out?

14. density Density of a substance is a characteristic property
This means that density will always be same for that substance no matter the size or amount.
Example: The density of H2O is always 1g/ml or 1g/cm3

15. THINK Minds on! Explain this, if you can
Hint, density is involved and something else that can affect the density of a liquid.
THINK