1. Density and Temperature

2. What is Density??

3. What is density? Density is mass per unit volume of a substance
Ice floats in water because Ice is less dense than water
Liquids with low densities will float on top of substances that are more dense
Density= Mass/Volume
Units:
Mass grams (g)
Volume  milliliters (mL) or Cubic centimeters (cm3)

4. Density

5. Two Ways to Volume Volumes of Solids
We use the formula specific to their shape
Cylinders =  x r2 x h
Blocks = l x w x h
Volumes of liquids
We use water displacement

6. Sample Problem 1
Calculate the density of a material that has a mass of g and a volume of 13.5 cm3.
D = ???
M = g
V = 13.5 cm3
D = /13.5
D=  3.89g/cm3

7. Sample Problem 2
The density of silver is g/cm3.  If a sample of pure silver has a volume of cm3, what is the mass?
 D = g/cm3
M = ???
V = cm3
10.49 = M /  M = D x V   g

8. Practice on Your Own
A student finds a rock on the way to school.  In the laboratory he determines that the volume of the rock is 22.7 mL, and the mass in g.   What is the density of the rock?
What is the mass of a 350 cm3 sample of pure silicon with a density of g/cm3?
The density of lead is g/mL.  What would be the volume of a g sample of this metal?

9. Temperature
Temperature: The measurement of the AVERAGE KINETIC energy of a particle.
Scientists use two equivalent scales: Celsius and the Kelvin.
Absolute Zero: Theoretically the point at which all particle motion ceases. Zero Kelvin
For WATER:
On the Celsius scale:
The Freezing point is ZERO the boiling point is 100.
On the Kelvin scale:
The freezing point is and the boiling point is

10. Temperature Conversions
Celsius To Kelvin
Kelvin to Celsius
Formula: K = ºC + 273
EX: Covert 23º C to K
K = = 296 K
Formula: ºC = K – 273
EX: Convert 400K to Celsius
ºC = = 127

11. Practice Convert the Celsius temperatures to Kelvin: -50ºC 100ºC 32ºC
Convert the Kelvin temperatures to Celsius:
150K
300K
125 K
25 K