The International Unit (SI) is a modern form of the metric system and is currently the most commonly used measurement system. This system consists of a coherent measurement system consisting of 7 base units and defines 22 units and many more derivatives.
Meanwhile, the SI base unit is the seven units of measurement defined by the Systeme International d’Unites , as the basic set to derive all other SI units, namely SI derived units. This basic unit is commonly used in various measurements, such as measuring height, weight, time and many others.
Here are 7 basic units for the international system (SI) :
- Long. Dimensions of an object which expresses the distance between ends, with the SI base unit meters (m).
- Mass. A quantity representing weight, with the SI basis of the kilogram (kg).
- Time. The entire sequence during which a process, action, or state exists or takes place, has the SI base unit second (s).
- Temperature. Indicator of the degree of heat of an object, has units of kelvin (K).
- Electric current. The amount of electric charge caused by the movement of electrons flowing through a point in an electric circuit over time, in the SI base unit amperes (A).
- Light intensity. The basic physical quantity in measuring the power emitted by a light source in a certain direction per unit angle, has units of candela (cd).
- Amount of substance. A physical base unit that measures the number of elementary samples which can be atoms, electrons, ions, molecules, or certain particles, with the SI base unit mole (Mol).
| No. | Basic Quantity | Unit Name | Unit Insignia | Magnitude Symbol |
| 1 | Long | Meter | m | l |
| 2 | Mass | Kilogram | Kg | m |
| 3 | Time | Second | s | t |
| 4 | Temperature | Kelvin | K | T |
| 5 | Electric current | Ampere | A | I |
| 6 | Light intensity | Candela | CD | j |
| 7 | Amount of substance | Mole | mole | n |
The five of the units of the international system of units are commonly used in chemistry, namely length, mass. Temperature, time and amount of substance.
Summary
- The International System of Units (SI) is a modern form of the metric system and is currently the most commonly used measurement system.
- In international units there are seven basic quantities used, namely length, mass, time, temperature, electric current, light intensity, and amount of substance.
- Five of the basic SI quantities are commonly used in chemistry.