SI System Today we're going to begin our unit on measurement. In this unit, you are going to need a calculator.

Like biologists, chemists have their own "language." SI System Like biologists, chemists have their own "language." Chemists measure the outcomes of their experiments in the International System of Units, or SI (French)

Base Units In the SI system, scientists use 5 base measurements: ·Meter - Distance ·Kilogram - Weight ·Kelvin - Temperature ·Second - Time ·Mole - Amount

Prefixes With the SI system, prefixes are of huge importance. Common Prefixes ·Mega - 1 million times larger ·kilo - 1000 times larger ·deci - 10 times smaller ·centi - 100 times smaller ·milli - 1000 times smaller ·micro - 1 million times smaller ·nano - 1000 million times smaller ·pico - 1 trilllion times smaller

Volume Volume can be tricky. There are four units scientists use for volume: ·Liter - base unit, all others "based" off it ·Milliliter - 1000 of these equals a liter ·Cubic cm - 1 cm3 equals 1 ml ·Microliter - 1 million of these equals a liter

There is a large difference between mass & weight. Mass vs. Weight There is a large difference between mass & weight. ·Mass is a measurement of the amount of matter something contains ·Weight is the measurement of the pull of gravity on an object. ·Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. ·Weight is measured on a scale. ·The Mass of an object doesn't change when an object's location changes. ·Weight, on the otherhand does change with location.

Differences in Kelvin vs. Celsius Temperature Remember, hot = expansion, cold = contraction Differences in Kelvin vs. Celsius ·Boiling points and freezing points of water ·Kelvin has absolute zero at 0 K - nothing known to be that cold ·To get from K to C, subtract 273 degrees ·To get from C to K, add 273 degrees

Energy Energy is not something we're going to delve in to too deeply, we'll leave that for physics. You should know the joule & calorie are the units. 1 calorie raises water temperature by 1 degree Celsius 1 J = .239 calories 1 calorie = 4.184 J