Refrigerant and fitness tracker: what they have in common

1. Step 1. Refrigerant — is made of — Ammonia. Ammonia was one of the first refrigerants.
2. Step 2. Ammonia — is made of — Hydrogen. Hydrogen.
3. Step 3. Hydrogen — is material for — Weather balloon. Filled with hydrogen or helium.
4. Step 4. Weather balloon — is made of — Vulcanized rubber. The envelope is rubber or latex.
5. Step 5. Vulcanized rubber — is material for — Fitness tracker. The strap is silicone.

Open Evothings