SI system
From Chemistry Resource
In the SI system, prefixes are used to represent multiples of 10 or fractions of 10 of the base units. The following table summarizes the basic prefixes that you should know.
| PREFIX | MULTIPLE | SCIENTIFIC NOTATION | ABBREVIATION |
|---|---|---|---|
| mega- | 1,000,000 | 106 | M |
| kilo- | 1,000 | 103 | k |
| deci- | 0.1 | 10-1 | d |
| centi- | 0.01 | 10-2 | c |
| milli- | 0.001 | 10-3 | m |
| micro- | 0.000001 | 10-6 | µ |
| nano- | 0.000000001 | 10-9 | n |
These prefixes can be applied to the base units:
Contents
Mass - base unit of gram
| PREFIX | MULTIPLE / SCIENTIFIC NOTATION | MASS | GRAM EQUIVALENT (conversion factor) |
|---|---|---|---|
| mega- | 1,000,000 or 106 | Mg (megagram) | 1 Mg = 1,000,000 gram |
| kilo- | 1,000 or 103 | kg (kilogram) | 1 kg = 1,000 gram |
| deci- | 0.1 or 10-1 | dg (decigram) | 1 dg = 0.1 gram |
| centi- | 0.01 or 10-2 | cg (centigram) | 1 cg = 0.01 gram |
| milli- | 0.001 or 10-3 | mg (milligram) | 1 mg = 0.001 gram |
| micro- | 0.000001 or 10-6 | µg (microgram) | 1 µg = 0.000001 gram |
| nano- | 0.000000001 or 10-9 | ng (nanogram) | 1 ng = 0.000000001 gram |
Some approximate sizes:
- a cup of coffee weighs approximately 250 grams
- a pinch of salt weighs approximately 1 milligram
- a 10-pound bag of potatoes weighs approximately 4.5 kilograms
Length - base unit of meter
| PREFIX | MULTIPLE / SCIENTIFIC NOTATION | MASS | METER EQUIVALENT (conversion factor) |
|---|---|---|---|
| mega- | 1,000,000 or 106 | Mm (megameter) | 1 Mm = 1,000,000 meter |
| kilo- | 1,000 or 103 | km (kilometer) | 1 km = 1,000 meter |
| deci- | 0.1 or 10-1 | dm (decimeter) | 1 dm = 0.1meter |
| centi- | 0.01 or 10-2 | cm (centimeter) | 1 cm = 0.01 meter |
| milli- | 0.001 or 10-3 | mm (millimeter) | 1 mm = 0.001 meter |
| micro- | 0.000001 or 10-6 | µm (micrometer) | 1 µm = 0.000001 meter |
| nano- | 0.000000001 or 10-9 | nm (nanometer) | 1 nm = 0.000000001 meter |
In addition to the SI unit of base unit of length, meter, a unit of length that is commonly used Chemistry is the angstrom. The abbreviation for angstrom is Å.
Conversion factor: 1Å = 10-10 meter
Some approximate sizes:
- a penny is approximately 2 centimeters in diameter
- an average adult is approximately 1.7 meters
- the thickness of hair is approximately 60 micrometer
- a piece of paper is approximately 0.1 millimeter
- one full twist of the DNA molecule is 3-4 nanometer
Volume - base unit of liter
| PREFIX | MULTIPLE / SCIENTIFIC NOTATION | MASS | LITER EQUIVALENT (conversion factor) |
|---|---|---|---|
| mega- | 1,000,000 or 106 | ML (megaliter) | 1 ML = 1,000,000 liter |
| kilo- | 1,000 or 103 | kL (kiloliter) | 1 kL = 1,000 liter |
| deci- | 0.1 or 10-1 | dL (deciliter) | 1 dL = 0.1 liter |
| centi- | 0.01 or 10-2 | cL (centiliter) | 1 cL = 0.01 liter |
| milli- | 0.001 or 10-3 | mL (milliliter) | 1 mL = 0.001 Liter |
| micro- | 0.000001 or 10-6 | µL (microliter) | 1 µL = 0.000001 liter |
| nano- | 0.000000001 or 10-9 | nL (nanoliter) | 1 nL = 0.000000001 liter |
Some approximate sizes:
- a soft drink can holds approximately 350 milliliters of pop
- 20 drops from a medicine dropper is approximately 1 milliliters
- a cup holds approximately 250 milliliters
- a teaspoon holds approximately 5 milliliters of liquid
External link
Content suitability
BCIT courses: CHEM 0011
