Classify the below substances based on their natural physical state (Solid or Gas).
Methane, Gold, Silver, Platinum
Solid - old, Silver, Platinum
Gas - Methane
### Instruction: Classify the below substances based on their natural physical state (Solid or Gas).
Methane, Gold, Silver, Platinum
### Context: 
### Answer: Solid - old, Silver, Platinum
Gas - Methane</s>