SI units: Difference between revisions

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SI units (Système international d'unités) are now the general fundamental units for scientific work. They are based on seven base units for seven base quantities which we assume to be mutually independent. The main basic units with which you will be concerned are the meter (m), the kilogram (kg) and the second (s). Other non-SI units, notably [[Minute|minute]] (min), hour (h), degree [[Celsius|Celsius]] (°C) and [[Litre|litre]] (l) are still commonly used in science.  
SI units (Système international d'unités) are now the general fundamental units for scientific work.&nbsp;They&nbsp;are based&nbsp;on seven base units for seven base quantities which we&nbsp;assume to be mutually independent.&nbsp;The main basic units with which you will be concerned are the meter (m), the kilogram (kg) and the second (s). Other non-SI units, notably [[Minute|minute]] (min), hour (h), degree [[Celsius|Celsius]] (°C) and [[Litre|litre]] (l) are still commonly used in science.<br>


<br>
The Seven Base Units are as Follows:<br>  
 
The Seven Base Units are as Follows:  
 
<br>


<u>'''Base Quantity&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;Symbol'''</u>  
<u>'''Base Quantity&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Name&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;Symbol'''</u>  
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Luminous Intensity&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; candela&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cd  
Luminous Intensity&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; candela&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cd  
<br>


When using abbreviations, never add the letter "s" in an attempt to signify plurals. Below are some of the common symbols:  
When using abbreviations, never add the letter "s" in an attempt to signify plurals. Below are some of the common symbols:  
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<br>
(1 l = 10<sup>3</sup> ml = 10<sup>6</sup> μl, 1g = 10<sup>3</sup> mg = 10<sup>6</sup> μg)
<br>


<br><br>
(1 l = 10<sup>3</sup> ml = 10<sup>6</sup> μl, 1g = 10<sup>3</sup> mg = 10<sup>6</sup> μg)

Revision as of 06:04, 26 November 2014

SI units (Système international d'unités) are now the general fundamental units for scientific work. They are based on seven base units for seven base quantities which we assume to be mutually independent. The main basic units with which you will be concerned are the meter (m), the kilogram (kg) and the second (s). Other non-SI units, notably minute (min), hour (h), degree Celsius (°C) and litre (l) are still commonly used in science.

The Seven Base Units are as Follows:

Base Quantity                              Name                 Symbol

Length                                          meter                       m

Time                                             second                    s

Mass                                            kilogram                  kg

Amount of Substance                     mole                       mol

Thermodynamic Temperature          kelvin                       K

Electric Current                              ampere                    A

Luminous Intensity                         candela                    cd

When using abbreviations, never add the letter "s" in an attempt to signify plurals. Below are some of the common symbols:

Symbol Prefix Factor
c centi 10-2
m milli 10-3
μ micro 10-6
n nano 10-9
p pico 10-12


(1 l = 103 ml = 106 μl, 1g = 103 mg = 106 μg)

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