Molecular Vibrations spring force spring force ○00000 stretched compressed equilibrium bond length Copyright 2010 Pearson Prentice Hall,Inc. If the bond is stretched,a restoring force pulls the two atoms together toward their equilibrium bond length. If the bond is compressed,the restoring force pushes the two atoms apart. If the bond is stretched or compressed and then released,the atoms vibrate. Chapter 12 8Chapter 12 8 Molecular Vibrations • If the bond is stretched, a restoring force pulls the two atoms together toward their equilibrium bond length. • If the bond is compressed, the restoring force pushes the two atoms apart. • If the bond is stretched or compressed and then released, the atoms vibrate