A Look at Density and How to Calculate It. The RATIO of the mass of a substance to the space it...
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Density A Look at Density and How to Calculate It
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Transcript of A Look at Density and How to Calculate It. The RATIO of the mass of a substance to the space it...
Density
A Look at Density and How to Calculate It
Definition of DENSITY: The RATIO of the mass of a substance to
the space it takes up (volume)
Substances have a characteristic density
Determined by how compact the atoms are inside
The maximum density of MOST materials occurs in the SOLID phase…
solids have high densitiesgases have low densities
Can you think of an exception to this rule?
What happens to the molecules in liquid water as water freezes?
Molecules move farther apart and EXPAND!
Ice (solid water) is LESS dense than liquid water
It floats in liquid water!
Will it Float? Density can
predict if something will float.
How?
Will it Float? The density of
liquid water is 1 g/mL.
Objects with a HIGHER density than water will ________.
Think of some examples…
It Floats If it has LOWER
density, it will ________.
Think of some examples…
Other factors that affect DENSITY:
The density of a GAS varies with pressure and temperature:• Higher temperature – molecules farther
apart – LESS dense• Lower temperature – molecules closer
together – higher pressure - MORE dense
Units for Density Just like length, volume and mass,
density has to be labeled with the correct unit…
g/cm³ or g/mL is the standard unit for density. 1cm³ = 1mL
