The green flame can be produced by several compounds and elements, primarily due to the presence of certain metal ions. Here are some common sources:
1. **Copper Compounds**:
- **Copper(II) sulfate (CuSO₄)**: When burned, it produces a green flame.
- **Copper(II) chloride (CuCl₂)**: Also produces a green color.
2. **Boron Compounds**:
- **Boron (B)**: When burned or vaporized, boron can produce a green flame.
3. **Lithium