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?
Yeah, personally I would say that it’s per kg bodyweight.
But I would also do my darndest to try write it, since “ng/kg” is kind of just nonsense. It makes it look like you could divide the grams out of that to get a fixed ratio, which is not correct at all.
But it is a fixed ratio.
If it was in pounds, metric tons, moles or atomic mass units… It doesn’t change the ratio, the actual number.
Would it be acceptable to drop the unit all together?
“Lethal dose is 0.000000012 : 1 (substance : bodyweight)” (I made up the number).
I’m not sure if there is a better way of writing the ratio.
Could a fraction be more applicable?
“lethal dose is 1/600000 of bodyweight”
I’m sure it’s written as
ng/kgto show the base units are the same, and the rest is just “fiddling” scientific notationwould not work, as they are no mass unit. 1 mol of Botox does not have the same weight as 1 mol of human (If that is defined at all, as organisms are no pure substances).
Well, what I meant with that, is that it’s semantically important that it’s
ng of the substanceperkg bodyweight.If it was
ng of the substanceperkg of the substance, then in proper mathematical physics, the unit would disappear completely.So, for example:
42000000000
ng of the substance/kg of the substanceIs equivalent to:
42000000000 * 0.000000001 *
kg of the substance/kg of the substanceWhich means in the end, you just have: 42
As my physics teacher would often say: Is that 42 potatoes or sausages or what is it?
A number without a unit is just devoid of meaning…