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DENSITY There are three states of matter: solid liquid gas Density – the amount of matter that occupies space Solids Molecules close together Liquids Molecules spread out further Gas Molecules spread far apart To determine density, you must divide the mass by the volume. D = m÷v Mass is measured in grams using a triple beam balance… or a digital scale. We can determine the mass of the box using the digital scale. 750 g Volume of a regularly-shaped object can be measured using a ruler. If the object has smooth sides where a ruler can be used to measure the length, width, and height, it is considered regular-shaped. Volume = length x width x height 2 cm 5 cm 15 cm V=lxwxh V = 15 cm X 5 cm X 2 cm V = 150 3 cm Determine the volume of the cube. 3 cm V=lxwxh V = 3 cm X 3 cm X 3 cm V = 27 3 cm Volume of a liquid is measured in mL using a graduated cylinder or a beaker. Objects that do not have smooth sides to measure are called irregular-shaped. To measure the volume of these objects we use water displacement. Water is put into a graduated cylinder and the volume of the water is measured. 50 40 30 20 10 The object is placed in the graduated cylinder. 50 40 30 The volume of the water and the object is determined. 20 10 The first volume is subtracted from the second volume. 40 mL – 29 mL = 11 mL The volume of the object is 11mL. Density does not depend on the amount of the substance. The density of the block is 16 g/cm3 If it is cut in half, what happens to the density? Density of block is 16 g/cm3 Density of block is 16 g/cm3 Sulfur Hexafluoride & Density Sulfur Hexafluoride & Density The density of water is 1g/mL. If an object with a density of less than 1g/mL is placed in the water, it will float. If an object with a density of greater than 1g/mL is placed in the water, it will sink. DENSITY Alcohol Oil Water COLUMN Can you give an estimation of the density of the alcohol and the oil? Density = 1g/mL DENSITY COLUMN Alcohol Oil Water Density = 1g/mL The density of the oil is less than 1 g/mL. The density of the alcohol is less than the density of the oil. DENSITY COLUMN Alcohol Density = .75 g/mL Oil Density = .96 g/mL Water Estimate the density of the piece of wood. The density Density = 1g/mL of wood is .8 g/cm3. DENSITY COLUMN Alcohol Density = .75 g/mL Oil Density = .96 g/mL Water Estimate the density of the piece of ice. The density Density = 1g/mLof ice is .9 g/cm3.