Evaluation of isotopic composition is for most but not all commercial samples.

It will then contribute in that way to the natural isotopic composition of a chemical element.

The array to the far left mimics the lead isotopic compositions at 130Myr.

Substantial deviations from the given atomic mass and isotopic composition can be found.

It has a characteristic terrestrial isotopic composition and thus an atomic mass can be given.

Mass spectrometry is also used to determine the isotopic composition of elements within a sample.

Isotopologues are molecules that differ only in their isotopic composition.

This makes it possible also to study the isotopic composition of a sample with infrared spectrophotometry.

Geologically exceptional samples are known in which the isotopic composition lies outside the reported range.

Fast neutron reactors can use plutonium of any isotopic composition.