dENSITY

Research: The word density means the degree of compactness of a substance. There is density in everything in your everyday life (matter.)The formula to find density is d=m/v.The density of solids and liquids is usually stated as g/cm3, while gases are usually stated as kg/m3. A real life example of density would be that ice floats on water because it is less dense than water, or it sinks because it is more dense than water. The only substance that breaks this rule is ice. Archimedes was the first person to develop the idea of density, to find out if his crown was truly made of gold. He figures this out because he knows that the formula of density for gold is 19.3 g/cm3, and if a different type of metal was used, it would make the density higher or lower than 19.3g/cm3. In some cases, you can manipulate density. If you can change the weight or volume, the density will change because the formula for density has these variables. An example of this would be to make an aluminum foil boat, and place it on the water. It floats, because it is less dense than water. You then crumple up the aluminum foil, and it sinks because it is now less dense than water.This happens because you changed the volume, which is part of the density formula.
State
Material
Density
(g/cm3)
Solids
Gold
19.3

Iron
7.8

Aluminum
2.7

Ice (0°C)
0.92
Liquids

Mercury
13.6

Seawater
1.03

Water (5°C)
1.00

Ethyl alcohol
0.81
Gases
(at normal pressure and a given temperature)
Density
(kg/m3) Air (0°C)
1.29

Air (10°C)
1.25

Hydrogen (0°C)
0.090

Helium (0°C)

Sources:http://www.school-for-champions.com/science/density.htm#.Ut1gB9LnYcE

http://www.encyclopedia.com/topic/density.aspx#2

http://socratic.org/chemistry/measurement-in-chemistry/density/density-a-story-of-archimedes-and-the-gold-crown

http://www.newton.dep.anl.gov/askasci/eng99/eng99421.htm http://socratic.org/chemistry/measurement-in-chemistry/density/density-a-story-of-archimedes-and-the-gold-crown