Chapter 3 Notes Part I Quantitative/qualitative Accuracy/precision Standard Units & Metric Conversions

Types of Measurements Qualitative-measurements describing the qualities or characteristics of something Quantitative-measurements that focus on actual numerical data

What type of data is the following: The beaker is hot. The beaker is 37 o C. A yellow precipitate forms. Water has a density of 1.0g/ml.

Accuracy vs. Precision Accuracy-how close a measurement is to the actual value. Precision-how close a set of measurements are to each other.

What is an example of: -something both accurate and precise. -something precise but not accurate. -something accurate but not precise.

What is the Metric System? Based on factors of ten Also Called International System (SI)

Why use metrics in science? Factors of ten are much easier to work with. Research does not just occur in the U.S.—a global community requires a universal measuring system.

Standard Units Length Mass Time Temperature Amount of substance

Standard Units Length - meter Mass - kilogram Time - second Temperature - °C Amount of substance - mole

Derived Units Area Volume Density Concentration Energy

Derived Units Area – square meter Volume – cubic meter Density – kg/m 3 Concentration – moles/Liter Energy - Joules

Metric Prefixes Each prefix signifies an amount of base units represented. Remember: King Henry…

Kilo-1000 Hecto-100 Deka-10 Base unit Deci-.1 or 1/10th Centi-.01 or 1/100th Milli-.001 or 1/1000th

Other prefixes Mega Giga Tera Micro or 1/ th Nano or 1/billon Pico