Percent Error Indicates accuracy of a measurement.
Percent Error Julie determines the density of copper to be 8.25 g/cm 3. Find the % error if the actual density of copper is 8.92 g/cm 3. % error = 7.51 %
Precision This is the repeatability of a measurement. It may or may not be accurate But everyone who does it gets the same answer
Accuracy vs. Precision Which of the following will allow measurement of a liquid’s volume with the greatest precision? A 50 mL cylinder graduated in 1 mL increments B 50 mL cylinder graduated in 0.5 mL increments C 100 mL cylinder graduated in 1 mL increments D 200 mL cylinder graduated in 5 mL increments Answer: B
Significant Figures (Sig Figs) Indicate precision of a measurement. Recording Sig Figs –Sig figs in a measurement include the known digits plus a final estimated digit 2.33 cm
If the decimal is present, start on the Pacific side at the first nonzero digit and count it and all the digits to the right of it. If the decimal is absent, start on the Atlantic side at the first nonzero digit and count it and all the digits to the left of it. Pacific (Present) Atlantic (Absent)