The energy-separation curve for two atoms, a distance, r, apart is: U(r)=−A/r^m+B/r^n

Question

Derive and expression for the stiffness of the bond at the equilibrium spacing, in terms of A, B, m, n, and r0.
S=dF/dr at r=r0:

Answer 1

The energy-separation curve for two atoms, a distance, r, apart is: U(r)=−A/r^m+B/r^n

Derive and expression for the stiffness of the bond at the equilibrium spacing, in terms of A, B, m, n, and r0.
S=dF/dr at r=r0: