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Density. Density is…. A periodic property How did Mendeleev know there was a missing element? He calculated the densities and they increased down a family. So Remember:. Density: mass per unit volume A measure of how compact molecules are in a substance.
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Density is…. • A periodic property • How did Mendeleev know there was a missing element? • He calculated the densities and they increased down a family
So Remember: Density: • mass per unit volume • A measure of how compact molecules are in a substance. • Determines whether an object will sink or float in a fluid.
Archimedes Principle There is a relationship between an object being able to float (or buoyancy ) and the mass of the fluid that was displaced.
The amount of the fluid displaced depends on the density of the object versus the density of the fluid.
How to find the volume of an irregular shaped object • Measure a known amount of water in a graduated cylinder • Place the object in the water • Then find the volume of water it displaces in a graduated cylinder, by subtracting the initial volume from the final volume • Divide mass by volume
Solid Liquid Gas
For example: Density of water is 1 g/ml. Wood has a density of 0.6 g/ml; Therefore, wood floats in water.
Formula for Density Density = mass / volume or D = m/v.
m D v • Density = mass/volume • Volume = mass /density • Mass = density X volume
So now, let’s calculate the density for the Coke and Diet Coke. • Mass the Coke on the balance. • Then divide it by the volume (ml on the can) 3. Your final answer will be the density.
When you write density, the unit you use is (the number) g/ml For example: 3.4 g/ml