Question

The particles of a substance can have kinetic energy (KE) and potential energy (PE). Which equation best summarizes the internal energy (U) of the substance?​

Answer 1

Answer:

The internal energy of a substance is equal to the total amount of potential energy and kinetic energy of ALL the particles in the substance.

For example, when the temperature increases (more temperature means more energy), the kinetic energy of the particles in the substance increases.

And when we reach a point near a change of phase (like near fusion point) there is energy used to break the bonds between the particles, then we have an increase in potential energy.

Then we could write the internal energy as:

U = ∑(KEₙ) + ∑(PEₙ)

Where ∑(KEₙ) and ∑(PEₙ) are the sums of the kinetic energy and potential energy of all the particles in the substance.

Answer 2

Answer: U = KEtranslation + KEvibration + KErotation + PEintermolecular forces

Explanation: A P E X