Simplify the following text for a Grade 8 native English-speaking person.
Original: The kelvin is a unit of measurement for temperature . It is one of the seven base units in the International System of Units ( SI ) and is assigned the unit symbol K. The Kelvin scale is an absolute , thermodynamic temperature scale using as its null point absolute zero , the temperature at which all thermal motion ceases in the classical description of thermodynamics .
Simplified: This means that Kelvin is an absolute temperature scale , and scientists use this scale more than any other .