Part-per Million [ppm] to Part-per Quadrillion [ppq] Converter

Definition: Parts per million (ppm) is a way of expressing very dilute concentrations of substances. It represents the number of parts of a substance per million parts of the mixture.

History/origin: The concept of parts per million arose out of the need to express very small concentrations of substances in a convenient way. It is widely used in chemistry, environmental science, and engineering.

Current use: PPM is commonly used to measure the concentration of pollutants in air and water, the concentration of trace elements in materials, and the concentration of additives in food and beverages.

Definition: Part-per quadrillion (ppq) is a unit used to express extremely minute concentrations, representing one part of a substance per quadrillion parts of the mixture. It is used in highly specialized scientific fields where extremely low concentrations are of interest.

History/origin: The use of 'part per quadrillion' arises from the need to quantify concentrations that are far below those measurable in 'parts per trillion'. Its development is linked to advancements in analytical chemistry and other scientific disciplines allowing for the detection of extremely small quantities of a substance.

Current use: PPQ is used in specialized fields like astrophysics to describe concentrations of elements in stellar atmospheres, and in advanced materials science. The unit is rarely used in common applications due to the extremely low concentrations it represents.