Science / Marine Biology / PPT: A measure of the salt content of sea water in terms of kg salt per kg of water, reckoned in parts per thousand. A conductivity version of this measure is the PSU, which differs from PPT by very little, on the order of 0.02 PSU or less.

Protactinium (Pa)

Science / Periodic Table of Elements / Protactinium (Pa): Atomic number: 91, Atomic mass: 231.0359 g.mol -1, Electronegativity: 1.5, Density: 15.37 g.cm-3 at 20°C, Melting point: 1600 °C, Boiling point: unknown, Vanderwaals radius: unknown, Ionic radius: u MORE


Science / Marine Biology / Salinity: Number of kg of dissolved salts in one kg g of seawater, measured in parts per thousand. Actually this definition stands alongside another definition based upon water standards whose electrical conduc MORE

Practical Salinity Units (PSU)

Science / Marine Biology / Practical Salinity Units (PSU): A measure of the salt content of seawater (practical salinity), based upon electrical conductivity of a sample relative to a reference standard of sea water, which now happens to be a reference set of MORE