1. Due Today: Density Part 2 Pre-Lab Homework: 1. Density Short Report 2. Empirical Formula Pre Lab DENSITY PART II

2.  Determine the density of:  Unknown colored solution  Rubber stoppers  Become familiar with Excel  Compare precision and accuracy OBJECTIVE

3.  Accuracy – how close a measured value is to the true value  Precision (reproducibility) – How close the measured values are to one another  You can be precise without being accurate KEY TERMS

5.  Intensive Property – physical property that does not depend on size or quantity  Density  Temperature  Melting Point  Boiling Point KEY TERMS

6.  Extensive Property – directly proportional to the amount of material  Mass  Volume  Area  Energy KEY TERMS

7.  Physical Property –do not change the chemical nature of matter  Density  Color  Melting Point KEY TERMS

8.  Chemical Property –change the chemical nature of matter  pH  Reactivity with water  Heat of Combustion  Chemical Stability – hydrogen peroxide KEY TERMS

9.  Fundamental Measurement –basis for a system of measurement  Not derived from other measurements  Mass (g)  Length (m)  Temperature ( o C)  Time (seconds) KEY TERMS

10.  Derived Measurement –obtained from one or more fundamental measurements  Density (g/mL)  Area (cm 2 )  Speed (m/s) KEY TERMS