The various colors of candle flames

Candles are common items in our daily lives. Whenever we light a candle, we will be attracted by its wonderful flame. In fact, the color of a candle flame is not just a simple orange, it can show a variety of colors. This article will introduce you to the various colors of candle flames and the reasons for their formation.

1. Orange flame
Orange flame is the most common color of candle flames. When a candle is lit, its main component, paraffin, undergoes an oxidation-reduction reaction to produce a flame. The carbon contained in paraffin is one of the elements that form a colored flame. During the combustion process, the carbon in the paraffin combines with the oxygen in the air through a combustion reaction to produce carbon monoxide. Under the action of high temperature, carbon monoxide undergoes a further combustion reaction to produce an orange flame.

2. Blue flame
Compared to orange flames, blue flames are rarer. The reason why candle flames appear blue is that they contain metals or metal salts. When common metal elements such as copper, zinc, etc., or metal salts such as borax, boron glass, etc. are added to candles, after the candle is lit, metal ions or metal salts enter the combustion process. Due to the special properties of metal elements, the flame becomes a blue color.

3. Red flame
Similar to blue flame, red flame is also formed after adding specific metal elements or metal salts to the candle. Among them, adding strontium salt or lithium salt can make the flame appear red. After ignition, strontium salt and lithium salt release specific spectral lines, making the flame appear bright red

4. Green flame
Green flame is different from blue and red flames. It is usually caused by chemical reactions in the flame. For example, when borax is added to the candle and ignited, green flame will be produced. This is because the electrons released after the boron element in the borax burns excite the energy level of oxygen molecules in the flame, thereby producing green light.

5. Purple flame
Purple flame is the rarest candle flame color, and its chance of occurrence is relatively rare. When potassium compounds are added to the candle, purple flame will appear after the candle is ignited. Potassium compounds will decompose under high temperature, releasing potassium oxide and oxygen. Potassium oxide further excites oxygen molecules, making the flame appear purple.

Summary: The colors of candle flames vary. In addition to common colors, there are also blue, red, green and purple. The generation of these colors is related to the specific elements or compounds added to the candle. Understanding these different flame colors can help us gain a deeper understanding of the principles of flame chemical reactions, while also adding to the mystery and artistry of candles in our daily lives. Whether used for lighting or lit during festivals and celebrations, candles bring us joy and warmth with their colorful flames.