Supercapacitor and davy lamp: what they have in common
- Step 1. Supercapacitor — is made of — Graphite. Electrodes made of activated carbon.
- Step 2. Graphite — is a kind of — Carbon. A form of carbon.
- Step 3. Carbon — includes — Coal. Mostly carbon.
- Step 4. Coal — uses — Coal mine. Extraction.
- Step 5. Coal mine — uses — Davy lamp. Protection against methane explosions.