Question

Vibrational energy is (1) Partially potential and partially kinetic (2) Only potential (3) Only kinetic (4) Only vibrational

Short answer

The correct answer is (1) Partially potential and partially kinetic.

Step-by-step solution

Understand Vibrational Energy

Vibrational energy is the energy associated with the vibrational motion of atoms within a molecule. It involves both potential and kinetic energy.

Potential Energy in Vibrational Motion

Potential energy in vibrational motion arises when the atoms are displaced from their equilibrium positions, akin to the stretching or compressing of a spring.

Kinetic Energy in Vibrational Motion

Kinetic energy in vibrational motion is due to the atoms moving back and forth around the equilibrium position.

Conclusion

Based on the understanding that vibrational energy has both potential and kinetic components, we conclude that the correct statement is that vibrational energy is partially potential and partially kinetic.

Key concepts

Potential Energy

Potential energy is the energy stored in an object due to its position in a force field or its configuration. In the context of vibrational energy, this potential energy arises when atoms within a molecule are displaced from their equilibrium positions.
Imagine stretching a spring. The energy stored in this stretched spring is potential energy. Similarly, when molecular bonds are stretched or compressed, they store potential energy.
Potential energy is crucial because it determines the stability of the molecular structure. Without potential energy, molecules would not resist deformation, leading to unstable structures.

Kinetic Energy

Kinetic energy is the energy an object possesses due to its motion. For molecular vibrations, this means the energy due to the movement of atoms as they oscillate back and forth around their equilibrium positions.
When atoms move, they possess kinetic energy. The faster they move, the higher their kinetic energy. This continuous to-and-fro motion of atoms within a molecule contributes to the vibrational energy.
The balance between kinetic and potential energy is essential for understanding vibrational dynamics. While potential energy relates to the position, kinetic energy relates to the motion.

Molecular Motion

Molecular motion refers to the movement of atoms and molecules in different forms, such as translational, rotational, and vibrational motions. In vibrational motion, atoms within a molecule move periodically around their equilibrium positions.
Vibrational motion is characteristic of the energy states of molecules, with each vibrational mode corresponding to a specific energy level. As atoms vibrate, they interchange kinetic and potential energy continually.
Understanding molecular motion is essential for grasping concepts like vibrational energy. These motions influence various molecular properties, including heat capacity, phase transitions, and chemical reactivity.