The vapor from elemental mercury metal is a neurotoxin. Most dentists have levels of mercury in their urine of 10 micrograms per liter (1 microgram is 10^-6 grams), which is about twice that of their patients. The legal safe maximum exposure limit for mercury in urine is 4.053 x 10^17 atoms of mercury per liter of urine. Does this level mean that the average dentist is at risk for

mercury poisoning? In other words, is this amount, 10 micrograms per liter of urine, above or below the legal safe limit? Show your work and justify your answer.

10 micrograms per liter of urine is below the legal safe limit and the dentist is not at risk for mercury poisoning.

Explanation:

To calculate the number of moles, we use the formula:

We are given:

Given mass of mercury =        (Conversion factor: )

Molar mass of mercury = 200.6 g/mol

Putting values in above equation, we get:

According to mole concept:

1 mole of an element contains number of atoms

So, moles of mercury will contain = number of atoms.

We are given:

Legal safe limit for mercury in urine = atoms

Calculated amount of mercury in urine = atoms

As, the calculated amount of mercury in urine is less than the legal safe limit of mercury in urine. So, the average dentist is not at risk for mercury poisoning.

Hence, 10 micrograms per liter of urine is below the legal safe limit and the dentist is not at risk for mercury poisoning.

the answer is d. 74.02