1. 2.4- DENSITY - an important and useful physical property
Mercury
Mercury
platinum
Platinum
Aluminum
13.6 g/cm3
21.5 g/cm3
2.7 g/cm3

2. The most dense element is….
Osmium, coming in at … g / cm3

3. And the least dense…
Helium…..measuring in at g/L at STP

5. DENSITY Which is heavier? Brick Styrofoam
It depends on how tightly packed your particles are…
The more tightly packed = more dense
Independent of how much of it you have (1 g or 100 g you will still have the same Density!)
Brick
Styrofoam

6. Cool……
Example: A cubic inch of Styrofoam weighs less and has less material within it than a cubic inch of lead.
Both take up the same # of space in this world but the lead is much heavier thusly more dense.
Scientists hypothesize (educated guess without proof) that some stars have such a great density that a teaspoon full of their matter (the material that makes them what they are) weighs more than the entire planet Earth!

7. Density
The ratio of mass to volume for a substance.
D = M / V

8. Density Questions

9. A piece of wood has a mass of 11
A piece of wood has a mass of 11.2 g and a volume of 23 mL what is the density?
U= density
I = 11.2 g and 23 mL
Plan: D = g mL
# Denisty = 11.2 g
23 mL
= 0.49 g/mL

10. Calculating
A piece of wood has a density of 0.93 g/mL and a mass of 23 g what is the volume?
U = # mL
I = 0.93 g/mL and 23 g
Plan: Volume = mass/Density
# mL = 23 g
0.93 g/mL
= 25 mL

11. Density as a conversion factor
Aluminum has a density of 2.70 g/cm3
What is the mass of 25 cm3 of aluminum?
25 cm3
2.70 g X
= 68 g 1
cm3

12. Density is often used as a CF
See SWB for all the example questions….