You're asking about the state of copper at 20 degrees, but you need to specify the unit of measurement for the temperature. Is it:

* 20 degrees Celsius (°C)?

* 20 degrees Fahrenheit (°F)?

* 20 Kelvin (K)?

Here's why it matters:

* Copper's melting point is 1084.62 °C (1984.32 °F). This means at 20°C (68°F), copper is definitely a solid.

* Copper's boiling point is 2567 °C (4653 °F). So, even at 20°F, it would still be a solid.

Please clarify the temperature unit, and I can give you a precise answer!