On the microscopic scale, internal energy is correctly defined as energy stored in the __________.

bonds between atoms, but not in the motion of atoms

motion of objects visible to the eye

motion of atoms, and the bonds within atoms and molecules
motion of atoms, but not in the bonds between atoms
is it the last one?

third one?

of course, bonds and motion.

Nope, not the last one. Consider ice.

the second one?

you are guessing, stop it. What changes in materials require energy?

Yes, the correct answer is "motion of atoms, and the bonds within atoms and molecules." Internal energy, on the microscopic scale, encompasses both the kinetic energy of the atoms' motion and the potential energy stored in the bonds between atoms and molecules. To arrive at this answer, you can review the scientific understanding of internal energy, which is based on the study of thermodynamics and molecular interactions. It involves considering the behavior of atoms and molecules at a microscopic level and how their motions and interactions contribute to the overall energy of a system.