Select an element to see what color flame it produces when tested. This is a great way to identify unknown compounds in the laboratory!
Flame tests are a method used in chemistry to detect the presence of certain elements, primarily metal ions, based on the characteristic color the element gives to a flame.
When a compound containing a metal is heated in a flame, the electrons in the metal atoms absorb energy and get excited, jumping to a higher energy level. When these electrons return to their original energy level, they emit energy in the form of light. The color of this light is specific to each element, which makes flame tests a useful identification method.
| Element | Flame Color | Wavelength Range |
|---|---|---|
| Lithium (Li) | Crimson Red | 670 nm |
| Sodium (Na) | Intense Yellow | 589 nm |
| Potassium (K) | Lilac (Pale Purple) | 766-770 nm |
| Calcium (Ca) | Brick Red | 622 nm |
| Barium (Ba) | Apple Green | 524 nm |
| Copper (Cu) | Blue-Green | 450-540 nm |
| Strontium (Sr) | Crimson Red | 650-700 nm |
| Magnesium (Mg) | Bright White | Multiple wavelengths |
While flame tests are useful, they have some limitations:
Flame tests have practical applications beyond the classroom:
See how much you've learned about flame tests by taking this quiz!
1. What color flame is produced when sodium compounds are tested?
2. Which element produces a blue-green flame?
3. Why do different elements produce different colors in flame tests?
4. Which two elements might be difficult to distinguish using only flame tests?
5. In fireworks, which element would be used to produce a green color?
6. Which element produces a bright white flame that spans multiple wavelengths?
Match each element to its correct flame color. Click on an element, then click on the corresponding color.