density
DESCRIPTION
DENSITY. How dense is dense?. What’s the matter?. Matter exists in 3 main forms: solid liquid and gas. Density is the concentration of matter (atoms) in a substance. Silicon atoms. Density is a ratio. The density of an object is the ratio of its mass (g) to its volume (cm 3 or ml). A. B. - PowerPoint PPT PresentationTRANSCRIPT
DENSITYDENSITY
How dense is dense?
What’s the matter?What’s the matter?
Matter exists in 3 main forms: solid liquid and gas.
Density is the concentration of matter (atoms) in a substance.
Silicon atoms
Density is a ratioDensity is a ratio
The density of an object is the ratio of its mass (g) to its volume (cm3 or ml).
A B C
Density calculations Density calculations convert to metricconvert to metric
7 X 3.625 X 1.75in.
2.54cm = 1 inch
Length = ?
Width = ?
Height = ?
Volume = ?
454g = 1lb
Mass = 30.98lb
Mass = ?
Density equationDensity equation
Density = Mass Volume
D = M V
D
M
V
Density calculationsDensity calculations
7 X 3.625 X 1.75in.
2.54cm = 1 inch
Length = 17.78cm
Width = 9.21cm
Height = 4.45cm
Volume = ?
454g = 1lb
Mass = 30.98lb
Mass = 14,064.9g
WorkWork
Volume
17.78cm X 9.21cm X 4.45cm = 728.7 cm3
Volume = 728.7 cm3
Mass
30.98lb X 454g = 14,064.9g
1lb
Mass = 14,064.9g
More workMore work
D = M
V
D = 14,064.9g
728.7 cm3
D = ?
More workMore work
D = M
V
D = 14,063.9 g
728.7 cm3
D = 19.3 g/cm3
Are we correct?Are we correct?
Densities of Common Elements and Compounds
Substance Density(g/cm3 )
Water 1.00
Aluminum, Al 2.70
Iron, Fe 7.80
Gold, Au 19.30
Mercury, Hg 13.50
Effect of phase of matter on densityEffect of phase of matter on density
Most substances increase in density as they change from gas to liquid to solid.
Quite simply, the atoms are closest together in the solid phase.
gas liquid solidincreasing density
decreasing density
Water is an exceptionWater is an exception
ice liquid water water vapor
Water is densest as a liquid at 3.98oC. That’s why ice floats.
Size or shape does not affect the Size or shape does not affect the density of a substancedensity of a substance
= same density
= same density
Even when Even when cut, the cut, the density of a density of a substance substance remains the remains the same.same.
Factors that affect densityFactors that affect density
Temperature– Heat - pushes molecules apart– Cold - pushes molecules together
Pressure– Low - allows molecules to spread apart– High - pushes molecules together
It’s the volume that changes and density is dependent on the ratio d=m
v
Float?Float?
If the density of an object is less than the liquid it will float.
The lower the density of an object the higher it will float in the liquid.
Sink?Sink?
If the density of an object is greater than that of the liquid, it will sink.
??????
If an object and a liquid have the same density, the object can remain stationary anywhere in the liquid.
LayeringLayering
Liquids of different densities will form layers.
http://www.youtube.com/watch?v=-CDkJuo_LYs