1. Units and Prefixes

2. Common Units The units we use represent different kinds of scientific measurements. Common measurements (unit types) are: time, distance, volume, temperature, mass, energy, pressure, and # of particles

3. Common Units The table below organizes SI base units for each type of measurement. Unit Type Base Unit Unit Type Base Unit mass grams (g) time seconds (s) volume liters (L) temperature kelvins (K) distance meters (m) pressure atmospheres (atm) # particles moles (mol) energy joules (J)

4. King Henry Prefixes Prefixes are added to the base unit to communicate the scale of a measurement. Kilo- (K-) Hecto- (H-) Deka- (da-) Prefix (abbr.) deci- (d-) centi- (c-) milli- (m-) 1000x100x10xScale (1x = base) 0.1x0.01x0.001x Meter(-m) Liter (-L) Gram (-g)

5. Conversion Factors Conversion factors can be determined using this table. Kilo- (K-) Hecto- (H-) Deka- (da-) Prefix (abbr.) deci- (d-) centi- (c-) milli- (m-) 1000x100x10xScale (1x = base) 0.1x0.01x0.001x Meter(-m) Liter (-L) Gram (-g)

6. Practice Problems Convert 0.550 seconds (s) to milliseconds (ms).

7. Practice Problems Convert 6.54 kilometers (km) to meters (m).

8. Practice Problems Convert 32 hectograms to decigrams.

9. Practice Problems Convert 76 centiliters to dekaliters.