Categorize the following list of elements.
Platinum, Copper, Hydrogen, Iron
Platinum: Metal
Copper: Metal
Hydrogen: Non-metal
Iron: Metal
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Categorize the following list of elements.

### Response:
Platinum: Metal
Copper: Metal
Hydrogen: Non-metal
Iron: Metal