66. The distance between the centers of the two oxygen atoms in an oxygen molecule is \( 1.21 \times 10^{.3} \mathrm{~cm} \). What is this distance in inches?

To convert the distance between the centers of the two oxygen atoms in an oxygen molecule from centimeters (cm) to inches (in), follow these steps: 1. **Understand the Given Value:** The distance is given as \( 1.21 \times 10^{-8} \) cm. (Assuming the exponent is \(-8\) based on typical bond lengths.) 2. **Conversion Factor:** \( 1 \text{ inch} = 2.54 \text{ cm} \) 3. **Perform the Conversion:** \[ \text{Distance in inches} = \frac{1.21 \times 10^{-8} \text{ cm}}{2.54 \text{ cm/in}} \] \[ \text{Distance in inches} \approx 4.764 \times 10^{-9} \text{ in} \] Rounding to two significant figures: \[ \text{Distance in inches} \approx 4.8 \times 10^{-9} \text{ in} \] **Final Answer:** The distance is approximately 4.8 × 10⁻⁹ inches.