Final answer:
To find the number of argon atoms in 7.66 x 10^5 mmol of argon, divide the given amount by 1000, then use Avogadro's number to calculate the number of argon atoms.
Step-by-step explanation:
To find the number of argon atoms in 7.66 x 105 mmol of argon, we need to convert the given amount from millimoles to moles by dividing it by 1000. Then, we can use Avogadro's number, 6.022 x 1023 atoms/mol, to calculate the number of argon atoms.
7.66 x 105 mmol * (1 mol / 1000 mmol) * (6.022 x 1023 atoms / 1 mol) = 4.606 x 1023 argon atoms