Flame Tests
Virtual Lab Bench
Click a metal salt to hold it in the Bunsen burner flame.
Observations
Key Formulas & Variables
| Symbol | Meaning |
|---|---|
| E | Energy of the photon emitted when an electron drops to a lower shell (in J or eV) |
| h | Planck's constant (6.63 × 10−34 J·s) |
| f | Frequency of the emitted light (in hertz, Hz) |
| λ | Wavelength of the emitted light (e.g. Na = 589 nm yellow, Cu = 510 nm green) |
| c | Speed of light (3.0 × 108 m/s) |
Heat excites electrons to higher energy levels. When they fall back down, they release photons with specific wavelengths. Each metal ion has unique energy gaps, so each produces a different flame colour.
About Flame Tests
Flame tests are a qualitative analytical technique used to identify certain metal ions based on the characteristic colour they produce when heated in a flame. When a metal salt is placed in a Bunsen burner flame, the heat energy excites electrons in the metal ions to higher energy levels. As these electrons return to their ground state, they emit photons of specific wavelengths, producing visible light of a characteristic colour.
Different metal ions produce different colours because their electrons have different energy level spacings. For example, sodium ions produce a bright yellow flame at 589 nm, while copper ions produce a green flame. This principle is the basis of atomic emission spectroscopy and is widely used in both qualitative analysis and in applications like fireworks.
This experiment is part of VCE Chemistry Unit 1, which explores how the diversity of materials can be explained through atomic structure and bonding.