When a vote is taken to change the definition from being a specific lump of plutonium kept in a vault in Paris since 1889 to a scientific formula.
Other changes
In their vote, countries also unanimously approved updates to three other key units:
Other changes
In their vote, countries also unanimously approved updates to three other key units:
- The kelvin for temperature.
- The ampere for electrical current.
- The mole for the amount of a substance.