Colour change! Copper and Oxygen
When copper is heated in air, oxygen joins onto it and the orange metal turns black. Outdoors, copper slowly turns green instead.
The result
- What it makes
- Copper(II) oxide
- Equation
- 2Cu + O₂ → 2CuO
- When it happens
- When heated
Fun fact from Fizzy: The Statue of Liberty is made of copper. It used to be shiny orange-brown, and it turned green over time!