1. Chem-To-Go Lesson 3 Unit 1 DENSITY

2. DENSITY IS A PHYSICAL PROPERTY. Aluminum Density = 2.8 g/cm 3 Silver Density = 10.49 g/cm 3 Zinc Density = 5.61 g/cm 3 Notice: The 3 substances look alike. Physical property doesn’t just refer to appearance. Density is a simple physical property that has nothing to do with appearance. Instead, density is a ratio of mass over volume. It can be used to identify substances.

3.  Three Simple Steps: 1)Measure mass. 2)Measure volume. 3)Divide mass by volume. FINDING DENSITY D = M V

4.  On October Break, a student goes mining for gold in the North Georgia mountains. He sifts the silt and water in a creek bed and finds a shiny, golden metal. Did he strike it rich? Mass of his finding: 103,255 mg Volume of his finding: 5.35 mL Density of gold: 19.30 g/mL EASY DENSITY EXAMPLE Calculate the density of his finding. Is it gold? TIP: Since we’re going to compare to a given density, we need to make sure that our units match.

5.  What is the mass of a block whose density is 0.78 g/cm 3 and volume is 324 mm 3 ? MORE ADVANCED DENSITY EXAMPLE Given Information: Density of block = 0.78 g/cm 3 Volume of block = 324 mm 3 ALWAYS CHECK THE DENSITY UNITS IF GIVEN. DO THE UNITS MATCH? SOLUTION: 1.MAKE ALL UNITS MATCH THE DENSITY UNITS. 2.PLUG INTO THE EQUATION. 3.SOLVE THE PROBLEM USING BASIC ALGEBRA.