The Metric System

The Metric System is the most commonly used mesurement system in the world and in the scientific community. The metric system uses the units in the chart for measurement.

Kelvin? What's that you say? Kelvin is the unit that is used in most calculations in Chemistry. Celcius is also often used because of its easy conversion to and from Kelvin. Fahrenheit is the most common scale in the U.S., so converting among all three is necesssary.

Fahrenheit, Celcius, and Kelvin

• If you subtract 32 from the Fahrenheit temperature and multiply by 5/9 (or divide by 1.8) then it will convert to Celcius temperature.
• If you multiply the Celcius temperature by 9/5 (or 1.8) then add 32 it will give you the Fahrenheit temperature.
• Adding 273 to Celcius will give Kelvin, and subtracting 273 from Kelvin you will get Celcius.

The generic equations are as follows:

Example:

• (451^oF - 32) / 1.8 = 233^oC
• (20^oC * 1.8) + 32 = 68^oF
• 40^oC + 273 = 313 Kelvin

Note: Kelvin does not have a degree mark nor is it said with a degree.

Metric System Prefixes

One of the many reasons the metric system is used is for its easy ability to add prefixes that change the value of the unit. For example: the prefix kilo- on grams means that 1000 grams equals 1 kilogram. In the example the prefix mulitiplied the original unit's value by 1000 because that is what kilo- stands for. The chart shows the most used prefixes in italics and the least used in regular print. This chart can be used to find the prefix of whatever unit you are working with.

* If you are not using Netscape, the numbers that are after the 10 in the chart are superscripts

If you wanted to know how many meters are in 4 megameters the conversion chart could be consulted. You would discover that 1 megameter = 1000000 meters. So 4 * 1000000 = 4000000. Therefore 4 megameters = 4000000 meters. (This can also be accomplished by moving the decimal six places)

Other Examples:

• 15cm = .15m
• 235kg = 235000g
• 12mm = 1.2cm