Colored flames

Distinguish elements by their flame color!

10 minutes



  • Conduct the experiment on the plastic tray.
  • Remove protective gloves before lighting the splint (step 3).
  • Keep flammable objects and hair away from flame.
General safety rules
  • Clean all equipment after use.
  • Ensure that all empty containers are disposed of properly.
General first aid information
  • In case of inhalation: Remove person to fresh air.
  • In case of injury always seek medical advice.
Advice for supervising adults

FAQ and troubleshooting

I can’t insert the bottle nozzle.

Try using another bottle nozzle. It should fit snugly in the bottle. Of course, you can always ask an adult for help.

Can I use ordinary foil for this experiment?

If you look closely, you’ll notice that the foil from the set is much thicker than ordinary foil. Unfortunately, this makes it difficult to replace with foil from another source. We strongly recommend using the foil we provide – it should suffice to repeat the experiment several times.

I can't get the solid fuel out of the bottle.

Use a wooden stick from the set to mix the solid fuel well. This should help break up any lumps and allow you to measure the solid fuel as intended.

How should I pour the metal powders on the flame?

Point the bottle nozzle toward the flame at about a 30-40 degree angle. Gently tap the bottle to dislodge some powder into the flame. If this doesn’t seem to work, tilt the bottle at a steeper angle and tap slightly harder.

I have some copper and zinc powder left over after the experiment. Is there any way to reseal the bottles so I can repeat the experiment later?

The bottle nozzles are very secure, so it will be difficult to pull them out. If you would like to repeat the experiment in the near future, you can just carefully leave the bottles in an upright position. If this isn’t doable, you can try to find suitable caps from other sets. You can also place the bottle and the nozzle in a resealable plastic bag. Finally, examine the caps from the bottles with powders. If you pull out the white round plugs, these caps can be used for the bottles with nozzles.

Step-by-step instructions

Prepare some powdered zinc Zn and copper Cu.


Prepare some solid fuel.


Pour some of each metal powder over the flame and see what happens.



Dispose of solid waste together with household garbage.

Scientific description

When talking about metals, you likely think of solid substances with silvery lusters, used to build towering architectural structures and cars. Not about tinting a flame green and whitish-blue using copper Cu and zinc Zn powders, respectively. So what’s up with that? The Cu and Zn powders react with oxygen in the extreme heat of the flame to yield Cu2+ and Zn2+ ions. These ions take a lot of heat energy from the flame and release it in the form of light!

Chemists use this effect to determine which metals are present in a sample. But this requires careful study of a flame using special equipment—a spectrometer. This yields a characteristic ID for the element, known as its emission spectrum, which looks rather like a colorful barcode.

The green flame you see is due to copper's emission spectrum. Interestingly, several elements were discovered thanks to, and named for, their most intensive spectral line. For example, indium was named for its indigo-colored line, caesium for its blue line (Latin caesius—sky-blue), and rubidium for its bright red line (Latin rubidus—deep red).

That’s interesting!