객관식
A 3.00 mole sample of K_2S contains how many atoms of potassium?
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2. Atoms & Elements
Mole Concept
Multiple Choice
How many moles are present in 2.85 × 10^{20} atoms of iron (Fe)?
A
1.71 × 10^{-3} mol
B
6.02 × 10^{23} mol
C
2.85 × 10^{-20} mol
D
4.74 × 10^{-4} mol
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검증된 단계별 안내1
Identify the given quantity: 2.85 \(\times\) 10^{20} atoms of iron (Fe).
Recall that 1 mole of any substance contains Avogadro's number of particles, which is 6.022 \(\times\) 10^{23} atoms/mol.
Set up the conversion from atoms to moles using the relationship: moles = \(\frac{\text{number of atoms}\)}{\(\text{Avogadro's number}\)}.
Substitute the values into the formula: moles = \(\frac{2.85 \times 10^{20}\)}{6.022 \(\times\) 10^{23}}.
Perform the division to find the number of moles (do not calculate the final value here, just set up the expression).
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