how many moles of arsenic are in 1.204 x 10^24 atoms of arsenic?\na. 0.2 moles\nb. 5.0 moles\nc. 2.0…

Explanation:

Step1: Recall Avogadro's number

Avogadro's number ($N_A$) is $6.022\times 10^{23}$ atoms/mol.

Step2: Use the mole - atom conversion formula

The number of moles ($n$) is given by $n=\frac{N}{N_A}$, where $N = 1.204\times 10^{24}$ atoms. So $n=\frac{1.204\times 10^{24}}{6.022\times 10^{23}}$.

Step3: Calculate the number of moles

$\frac{1.204\times 10^{24}}{6.022\times 10^{23}}=\frac{1.204}{6.022}\times10^{24 - 23}= 2.0$ moles.

Answer:

C. 2.0 moles