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Density Density Take a look at the two boxes below. Each box has the same volume. If each ball has the same mass, which box would weigh more? Why? Density The box that has more balls has more mass per unit of volume. This property of matter is called density. The density of a material helps to distinguish it from other materials. Density I love density d = mass/volume (g/ml) m v Mass volume Density = Mass of substance per unit volume of the substance. Common units are g/cm3 or g/mL. mass Density = volume Example #1 A certain mineral has a mass of 17.8 g and a volume of 2.35 cm3. What is the density of this mineral? mass Density = volume 17.8 g Density = 2.35 cm3 3 Density = 7.57 g/cm Example #2 What is the mass of a 49.6-mL sample of a liquid, which has a density of 0.85 g/mL? Density = 0.85 g/mL = mass volume x 49.6 mL mass = x = 42 g Density More practice - Calculate the density of each block. Block I Mass = 79.43 grams Volume=29.8 ml Block II Mass = 25.41 grams Volume = 29.8 ml Density Block I Density = 79.43 grams / 29.8 ml = 2.67 g/ml Block II Density = 25.41 grams / 29.8 ml = 0.85 g/ml Density Density is a physical characteristic of a material and allows us to determine what each block is made of. All pieces of matter made of the same material will have the same density. Different matter will have different densities.