Rutherford (unit) Rutherford (unit) The rutherford (symbol Rd) is a non-SI unit of radioactive decay. It is defined as the activity of a quantity of radioactive material in which one million nuclei decay per second. It is therefore equivalent to one megabecquerel, and one becquerel equals one microrutherford. One rutherford is equivalent to 2.703 × 10 curie. The unit was introduced in 1946. It was named after British/New Zealand physicist and Nobel laureate Lord Ernest Rutherford (Nobel Prize in 1908), who was an early leader in the study of atomic nucleus disintegrations. After the becquerel was introduced in 1975 as the SI
Mole (unit) 1%. The name "mole" is an 1897 translation of the German unit "Mol", coined by the chemist Wilhelm Ostwald in 1894 from the German word "Molekül" (molecule). However, the related concept of equivalent mass had been in use at least a century earlier. The mole was made the seventh SI base unit in 1971 by the 14th CGPM. At the 26th CGPM the definition of the mole was changed from a number derived from a weight (the number of atoms in 12 grams of carbon-12, C) to directly being equal to Avogadro's constant. Since its adoption into the International System