Measurement

SI Units

Scientists use the same international system for measurement called SI units Short for Systeme Internationale d’Unites

(French) Helps scientists compare research from around

the world Built on 7 metric base units

SI Units

The Big 5

Measurement Unit

Length Meters (m)

Mass Kilograms (kg)

Time Seconds (s)

Amount Moles (mol)

Temperature Kelvin (K)

Metric Prefixes Metric prefixes are made to make base units larger or smaller

REMEMBER:

King Henry Died By Drinking Chocolate Milk

Prefix Unit Abbreviation

Meaning (__ plug in a base unit of g, L, or m)

Kilo k 1000 __ = 1 k__ (i.e. 1000 m = 1 km)

hecto h 100 __ = 1 h__

deca da 10 ___ = 1 da___

base (No Prefix) g or L or m Base unit

deci d 1 ___ = 10 d ___

centi c 1 ___ = 100 c ___

milli m 1 ___ = 1000 m ___

Temperature Conversions Temperature Scales

Fahrenheit (°F) Daily temp… not scientific

Celsius (°C) Freezing point of water = 0°C Boiling point of water = 100°C

Kelvin (K) SI unit of Temperature

Absolute Zero 0 K When all motion stops We have gotten to a millionth of a degree but never 0 K

Temperature Conversions

1 °C = 1 K

Changing FROM °C K

°C + 273 = K

Changing FROM Kelvin °C

K-273 = °C

Convert the Following…

25 ° C = ______ K

123 ° C = _______ K

853 K = _______ ° C

87.89 K = _______ °C

0 °C = _____ K

0 K = ______ °C

298

396

580

-185.11

273

-273

Density

Density – ratio of mass of an object to its volume

Density = MassVolume

The density of water = 1.0 g/mL If density is > 1, object will sink If density is < 1, object will float

Mass

VolumeDensity

Common Units:

Mass: g, kg, lbs

Volume: L, mL, gal., qt., cm3

Density: g/mL; lbs/gal; g/cm3

Density Column