Density represents the mass of an object or compound within a given volume.
Concept #1: Understanding Density
Density establishes a relationship between mass and volume.
Example #1: If the density of an unknown metal is 21.4 grams per cubic centimeters, express its density in pounds per cubic feet. Remember that 1 in = 2.54 cm.
Density questions can include dimensional analysis so remember to use the same approach as you would normally.
Example #2: A piece of unknown metal weighs approximately 0.45 lbs. When a scientist places it in a glass beaker the water level increases from 1.85 L to 2.13 L. What is the density of the palladium metal in g/mL?
In a water displacement question the volume of the water increases with the added volume of the unknown substance.
Practice: The U.S. Environmental Protection Agency sets the maximum safe level of lead in blood at 24 μg per dL of blood. The average person has 60 mL of blood per kilogram of body weight. For a 63.7-kg (140.459 lb) person, what is the total maximum safe content of lead in blood?