Convert Atomic Mass Unit (u) to Scruple (Apothecary) (s.ap) instantly.
About these units
Atomic Mass Unit (u)
The atomic mass unit (u) is defined as exactly 1/12 the mass of a neutral carbon-12 atom, which makes it approximately 1.66053906660 × 10⁻²⁷ kilograms. This definition allows scientists to express atomic and molecular masses in a convenient, intuitive scale that aligns with the structure of the periodic table. By anchoring the unit to carbon-12, chemists and physicists gained a universal reference point that harmonizes molecular weight, relative isotopic abundance, and mass spectroscopy results. The atomic mass unit effectively normalizes the complexity of atomic masses into whole-number or near-whole-number values for most nuclei. In chemistry, u is indispensable for calculating molar masses, reaction stoichiometry, and isotopic compositions. It is also used across nuclear physics, astrophysics, and biophysics, demonstrating the universality of atomic-scale measurement.
Scruple (Apothecary) (s.ap)
The scruple is an old apothecary unit equal to 20 grains or 1.2959782 grams, originating in ancient Greek and Roman medicine. Apothecaries used scruples for compounding herbal remedies, powders, and tinctures long before standardized metric systems were adopted. Its size made it ideal for preparing early pharmaceuticals where doses needed to be accurate but not excessively granular. Over centuries, the scruple appeared in medical recipes, early scientific writings, and even medieval charms and remedies. Although obsolete today, replaced by milligrams and grams, the scruple is vital for historians studying early medical texts, pharmacy records, and classical-era scientific practices.