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The International System of Units (SI) is an internationally recognized system. It brings together the most commonly used units of measurement in order to facilitate exchanges in the scientific, technological, and educational fields. The table below shows the most commonly used units of measure in science. Some of the basic units of the international system are shown in blue:
| Name of quantity measured | Unit of measurement name | Unit of measurement symbol |
| Gravitational acceleration |(g)| | Newton per kilogram | |\text{N/kg}| |
| Area |(A)| | Centimetre squared Metre squared Hectare | |\text{cm}^2| |\text{m}^2| |\text{ha}| |
| Angle (|\theta|) | Degree | |^{\circ}| |
| Specific heat capacity |(c)| | Joule per gram degree Celsius Kilojoule per kilogram degree Celsius | |\text{J/g} \cdot ^\circ \text{C}| |\text{kJ/kg} \cdot ^\circ \text{C}| |
| Heat |(Q)| | Joule | |\text{J}| |
| Electric charge |(q)| | Coulomb | |\text{C}| |
| Concentration |(C)| | Gram per litre Parts per million Percentage Mole per litre | |\text{g/L}| |\text{ppm}| |\%| |\text{mol/L}| |
| Potential difference |(U)| | Millivolt Volt | |\text{mV}| |\text{V}| |
| Distance |(d)| | Millimetre Centimetre Decimetre Metre Kilometre | |\text{mm}| |\text{cm}| |\text{dm}| |\color{blue}{\text{m}}| |\text{km}| |
| Energy |(E)| | Joule Kilojoule | |\text{J}| |\text{kJ}| |
| Force |(F)| | Newton | |\text{N}| |
| Current intensity |(I)| | Ampere Milliampere | |\color{blue}{\text{A}}| |\text{mA}| |
| Mass |(m)| | Milligram Gram Kilogram Tonne | |\text{mg}| |\text{g}| |\color{blue}{\text{kg}}| |\text{t}| |
| Molar mass |(M)| | Gram per mole | |\text{g/mol}| |
| Density (|\large{\rho}|) | Gram per millilitre | |\text{g/mL}| |
| Number of moles |(n)| | Mole | |\color{blue}{\text{mol}}| |
| Pressure |(P)| | Pascal Kilopascal Atmosphere Millimetre of mercury | |\text{Pa}| |\text{kPa}| |\text{atm}| |\text{mm Hg}| |
| Power |(W)| | Kilowatt Watt | |\text{kW}| |\text{W}| |
| Resistance |(R)| | Ohm | |\Omega| |
| Solubility |(s)| | Gram per litre Gram per 100 millilitres | |\text{g/L}| |\text{g/100mL}| |
| Temperature |(T)| | Degree Celsius Degree Fahrenheit Kelvin | |^\circ \text{C}| |^\circ \text{F}| |\color{blue}{\text{K}}| |
| Time |(t)| | Second Minute Hour | |\color{blue}{\text{s}}| |\text{min}| |\text{h}| |
| Work |(W)| | Joule | |\text{J}| |
| Speed or velocity |(v)| | Metre per second | |\text{m/s}| |
| Volume |(V)| | Cubic centimetre Cubic metre Millilitre Litre | |\text{cm}^3| |\text{m}^3| |\text{mL}| |\text{L}| |
For other units of measurement, it is possible to consult the following concept sheets:
The International System of Units (SI) provides certain prefixes for multiples and submultiples of units of measurement. The symbol for the new units of measurement formed is then composed of two symbols: that of the multiple and that of the unit of measurement :
| Prefix | Power | Symbol |
| Pico | |10^{-12}= 0.000\ 000 000\ 001| | |\text{p}| |
| Nano | |10^{-9}= 0.000\ 000 001| | |\text{n}| |
| Micro | |10^{-6}= 0.000\ 001| | |\mu| |
| Milli | |10^{-3}= 0.001| | |\text{m}| |
| Centi | |10^{-2}= 0.01| | |\text{c}| |
| Deci | |10^{-1}= 0.1| | |\text{d}| |
| Unit | |10^{0}= 1| | - |
| Déca | |10^{1}= 10| | |\text{da}| |
| Hecto | |10^{2}= 100| | |\text{h}| |
| Kilo | |10^{3}= 1000| | |\text{k}| |
| Mega | |10^{6}= 1\ 000\ 000| | |\text{M}| |
| Giga | |10^{9}= 1\ 000\ 000\ 000| | |\text{G}| |