Answer : The density in cg/L is, 55000 cg/L
Explanation :
Density : It is defined as the mass of a substance contained per unit volume.
The conversion used from gram to centigram is:
1 gram = 100 centigram
The conversion used from milliliter to liter is:
1 mL = 0.001 L
So,
1 g/mL =

As we are given the density 0.55 g/mL. Now we have to determine the density in cg/L.
As, 1 g/mL = 100000 cg/L
So, 0.55 g/mL =

Therefore, the density in cg/L is, 55000 cg/L