I know the ng means nanogram
But I’m curious how would I say the above line of 2.1 ng/kg
For context I got it from this paragraph
a lethal dose of 1.3–2.1 ng/kg in humans
Would it be
2.1 nanogram per kilogram?
Also if I wanted to write that as a decimal number how would i write that?
That assumes that the particles are the same mass for the drug and human.
You could say a small percent mass.
Yeah it’s typically not used for dosages, rather it’s for concentrations in solution. However strictly speaking the grams cancel in the units of ng/kg and you are left with ppt. I think of ppm and ppt as very small percentages anyway. As per cent means part per one hundred. Can’t use “permille” because it means part per thousand but sounds like part per million.
In the case of a lethal dose, I think it would be fine to say, “it’s lethal at a rate of 2 trillionths of body mass”.