HELP ME ASAP PLS, ( zoom in on the picture )

Explain why electric current cannot exist if a current doesn't have a voltage source.

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.

Which of the following best describes internal energy? a. the difference between the kinetic and potential energies of the particles in a system b. the sum of the kinetic and potential energies of the particles in a system c. the sum of the kinetic and thermal energies of the particles in a system d. the difference between the kinetic and thermal energies of the particles in a system