Flame Test Colors Chart
Visual guide to atomic emission. Identify metal ions by their characteristic flame colors with our virtual burner.
Lithium
Vibrant crimson flame. Used in red fireworks and flares. Emission due to 2p -> 2s transition.
Strontium
Deep scarlet red. A primary ingredient in red fireworks and road flares.
Calcium
Brick-red flame. Often appears more orange than strontium.
Sodium
Bright, persistent yellow. The 'D-line' emission is so strong it masks other colors.
Barium
Pale yellow-green flame. Used in green fireworks.
Boron
Vibrant green. Boric acid burns with a distinct green flame.
Copper (Halide)
Distinctive teal/cyan flame. Emitted by Copper(I) halides.
Selenium
Cool electric blue flame, distinct from the white-blue of lead.
Cesium
Sky-blue to violet flame. Named from the Latin 'caesius' meaning sky blue.
Potassium
Faint lilac (pink-purple). Often masked by sodium; viewed through cobalt glass.
Rubidium
Deep red-violet flame. Similar to potassium but more intense red.
Lead
Pale grayish-blue flame. Toxic fumes, handle with care.
Arsenic
Ghostly blue flame. Highly toxic.
Zinc
Often colorless or faint blue-green. Zinc metal burns with bright white sparks.
Magnesium
No flame color for ions, but metal burns with blinding white light (UV rich).
The Science of Atomic Emission
The dazzling colors of fireworks and neon signs come from the same principle: excited electrons. A flame test is a rapid diagnostic tool used in chemistry to detect the presence of certain metal ions based on their emission spectrum.
Excitation
Heat from the flame provides energy to the atom's electrons. They absorb this energy and jump from their Ground State to an unstable, higher-energy Excited State.
Relaxation
Electrons prefer stability. They essentially "fall" back down to lower energy levels almost instantly.
Emission
As they fall, they release the excess energy as a Photon of light. The energy of this photon determines its wavelength (color). High energy drop = Violet/Blue. Low energy drop = Red.
Common Pitfalls
Sodium Contamination: Sodium is everywhere (sweat, dust). Its yellow flame is so bright it can mask other colors. Always clean your wire loop thoroughly with HCl!
Color Blindness: Some colors like Lilac (K) and Red-Violet (Rb) are very similar. Use a spectroscope for definitive identification.
Frequently Asked Questions
What causes the colors in a flame test?
The heat from the flame excites electrons to higher energy levels. When they fall back to their ground state, they release energy as light. The color depends on the specific wavelength of this emitted light.
Why does Sodium turn the flame yellow?
Sodium emits intense yellow light at 589 nm (the "D line") due to the transition of its single valence electron. This emission is so bright it can mask other colors.
Why do we use Cobalt Blue Glass?
Cobalt blue glass filters out the intense yellow light from sodium impurities. This allows chemists to see fainter colors, like the lilac flame of Potassium, which would otherwise be hidden.
What is the ground state?
The ground state is the lowest energy arrangement of electrons in an atom. Electrons return to this state after being excited, releasing photons (light) in the process.
Can a flame test identify a mixture of ions?
It is difficult because one dominant color (like Sodium's yellow) usually masks others. Spectroscopes are better for mixtures as they separate the light into individual spectral lines.
Why is platinum or nichrome wire used?
These metals have high melting points and do not produce a flame color themselves (they are inert in the flame), ensuring they don't interfere with the test results.
Why dip the wire in Hydrochloric Acid (HCl)?
HCl is used to clean the wire and remove impurities. It also converts metal compounds into metal chlorides, which are usually more volatile (vaporize easier) and give better flame colors.
Is the flame test qualitative or quantitative?
It is a qualitative test. It tells you what elements are present (identity), but not how much (quantity) is there.
What color is the Lithium flame?
Lithium burns with a distinct Crimson Red flame.
What color is the Copper flame?
Copper (especially its halides) burns with a Blue-Green or Teal flame.