One million argon atoms is ________ mol (rounded to two significant figures)of argon atoms. A)3.0 B)1.7 × 10^-18 C)6.0 × 10²³ D)1.0 × 10^-6 E)1.0 × 10⁺⁶

Question

Quizplus · Accepted Answer

One mole of any substance contains 6.022 x 10²³ particles. Therefore, to find how many moles of argon atoms are in one million atoms, we divide one million by Avogadro's number:

1,000,000 / 6.022 x 10²³ = 1.7 x 10^-18 mol

We round this answer to two significant figures since the original number only had one significant figure. Choice B is the only option that matches this value.

One Million Argon Atoms Is ________ Mol (Rounded to Two