- [Royal Society of Chemistry — Silicon](https://periodic-table.rsc.org/element/14/)
  Primary material source for the silicon context; verify the specific semiconductor wording against the current source before publication.
- [Royal Society of Chemistry — Copper](https://periodic-table.rsc.org/element/29/Copper)
  Primary material source for copper context; the film uses copper as the conducting trace in an explanatory schematic.
- [U.S. Department of Energy — How Batteries Work](https://www.energy.gov/science/doe-explainsbatteries)
  Primary battery source for the lithium-ion storage role; verify the phone-specific wording against the current source before publication.
- [U.S. Department of Energy — Lithium-ion batteries](https://www.energy.gov/sites/default/files/Li-ion.pdf)
  Source for the rechargeable lithium-ion battery context used by the phone example.