A Dalton (Da) is a unit of mass used in the field of chemistry and molecular biology to express the molecular weight or mass of atoms, molecules, and compounds. It is named after John Dalton, a British chemist and physicist who contributed to the development of modern atomic theory.
One Dalton (Da) is defined as one twelfth of the mass of an unbound carbon-12 atom, which is roughly equivalent to 1.66053906660 x 10^-27 kilograms. This definition was adopted as the standard for atomic mass units (u) and is now used internationally.
Daltons are useful in the following contexts:
Atomic and Molecular Mass: The molecular weight or mass of a molecule is often expressed in Daltons. For example, the molecular weight of water (H2O) is approximately 18.01528 Da, which means that one molecule of water has a mass of approximately 18.01528 Daltons.
Proteomics and Biochemistry: In biology, particularly in the study of proteins, the mass of biomolecules like proteins and nucleic acids is often measured in Daltons. This is important for understanding their structure and function.
Mass Spectrometry: Mass spectrometry is a powerful analytical technique used to determine the mass and composition of molecules. Mass spectrometry results are often reported in Daltons.
Chemical Reactions: In chemical reactions, the mass of reactants and products can be expressed in Daltons to understand the stoichiometry of the reaction.
The term "ton assay" in the context of the United States typically refers to the assay ton, which is a unit of measurement used in the mining industry to express the amount of valuable material contained in a quantity of ore. This measurement is particularly common in the context of precious metals like gold and silver.
An assay ton is defined as 29.1667 grams (or approximately 1.04 ounces) of ore material. Miners and metallurgists use this unit to represent a standardized sample size for the purposes of analyzing the ore's composition and determining the percentage of valuable minerals or metals within it.
The use of the assay ton is essential in assessing the economic viability of mining operations and estimating the potential yield of valuable minerals from a given ore deposit. By analyzing a sample that is equivalent to one assay ton, miners and analysts can extrapolate the likely yield from a larger quantity of ore.
So, when you encounter the term "ton assay US," it generally refers to the assay ton used in the United States for mineral analysis and mining-related calculations.