Answer
$8.40 \times 10^2 N/m$
Work Step by Step
Use equation 11-6b to relate frequency, mass, and spring constant.
$$f=\frac{1}{2 \pi}\sqrt{\frac{k}{m}}$$
$$k=4 \pi^2f^2m $$
Using the mass of one oxygen atom, solve for k = $8.40 \times 10^2 N/m$.