Question

part a
how many moles of cu are in 1.48 × 10²⁵ cu atoms?
○ 6.022 × 10²³
○ 24.6
○ 0.0408
○ 1.54 × 10²⁵
○ none of the above

Explanation:

Step1: Recall Avogadro's number

Avogadro's number is \( 6.022 \times 10^{23} \) atoms/mol, which relates the number of atoms to moles: \( \text{moles} = \frac{\text{number of atoms}}{\text{Avogadro's number}} \).

Step2: Plug in the values

Given the number of Cu atoms is \( 1.48 \times 10^{25} \). So, moles of Cu \( = \frac{1.48 \times 10^{25}}{6.022 \times 10^{23}} \).

Step3: Perform the calculation

Simplify the exponents: \( 10^{25 - 23} = 10^2 \). Then, \( \frac{1.48}{6.022} \approx 0.2458 \), and multiply by \( 10^2 \): \( 0.2458 \times 100 = 24.58 \approx 24.6 \).

Answer:

24.6 (the option with "24.6")