Examples from the Web for deuterium
From that, they extracted the ratio of the number of deuterium atoms to the number of hydrogen atoms.
Deuterium is an isotope of hydrogen containing a proton and neutron in its nucleus, while normal hydrogen has only a proton.
However, even that ginormous difference still shows about three times the amount of deuterium than we see on our planet.
One chemical test involves measuring the relative amount of deuterium in water.
Then, for a considerably higher price, he would undertake to collect a sample of the deuterium they were using.
Well, heavy water is made of one atom of oxygen plus two atoms of deuterium, which is the first isotope of hydrogen.