# Density PP ```Learning Target:
Be able to explain how an object’s density is
related to its mass and volume both
mathematically (quantitatively) and in words
(qualitatively).
Learning Outcome: Complete “Density Lab”



An object’s density is related to the amount of
matter or “stuff” (mass) contained in a
corresponding unit of volume.
Density is a physical property of matter.
It is an Intensive property meaning density of a
material does not change depending on the
amount measured (see first slide).


Density is a ratio (mass/volume) with SI
dimensions [kg]/[m3]
For our class, we will mostly use units of
g/cm3
Substance
ρ [kg]/m3
Air
0.0013*
Ice
0.917
Water
1.00 (Sometimes used as Reference)
Aluminum (Al)
2.70
Iron (Fe)
7.86
Gold (Au)
19.3
*at 0o C and 1 atm Pressure
In general, density decreases as a substance moves from
solidliquidgas
Do you notice any exceptions above?


Density is related to buoyancy because objects less
dense than another (i.e. water) will float.
To calculate a relative density, just divide the
substance you are analyzing by a reference:
pH2O= 1.00kg/m3
pIce= .917kg/m3
.917/1.00 = .917
If the substance is less than the reference
(ratio is &lt; 1) it will float.
```