This Flame Rainbow video demonstration safely shares how different metal ions produce different flames. The team at Chem Talk prepared metal salts containing these different ions and lit them to reveal a rainbow of vibrant colors. An explanation via the Royal Society of Chemistry:
“When heated, the electrons in the metal ion gain energy and can jump into higher energy levels. Because this is energetically unstable, the electrons tend to fall back down to where they were before, releasing energy as they do so. This energy is released as light energy, and as these transitions vary from one metal ion to another, it leads to the characteristic colours given by each metal ion.”
The colors, in order: Strontium Sr2+, Lithium Li+, Calcium Ca2+, Sodium, Na+, Barium Ba2+, Boron B3+, Copper Cu2+ and Cu+, and Potassium K+.
The violet CH3OH is methanol, a toxic, extremely hazardous liquid that the salts have been soaked with to reveal the colors. This part of the experiment is dangerous and has resulted in severe classroom injuries.
In addition, flammable methanol vapors are heavier than air and can easily accumulate in confined spaces. tl;dr: Do not try this at home. Via the Canada Safety Council:
“Short-term exposure to methanol vapor can irritate the eyes, nose and throat and cause headache, nausea, throwing up, dizziness and trouble breathing.”
An additional safety note from Chemistry Talk:
“It is essential that containers of methanol are not kept anywhere remotely near open flames. This demonstration can only be performed by trained professionals, as it can be extremely dangerous. Accidents from methanol catching on fire have resulted in severe injury & death. The National Science Teaching Association (NSTA) recommends that methanol demonstrations are done only in a fume hood.”
Or use the video above and don’t worry about the prep, equipment, safety issues, or cleanup!
Find more Chem Talk chemistry demonstrations on YouTube, Instagram, TikTok, and at Chemistrytalk.org.
Watch these related chemistry and fire videos next:
• How is black fire made?
• Humphry Davy’s Potassium Volcano
• The Science Of Firework Color
• What’s the chemistry and physics of a flame?
• Candle Chemistry – ExpeRimental
• Don’t extinguish a metal fire with water
This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.
Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.