Have you ever wondered what happens to the wax when a candle burns? It's a fascinating process that involves both physical and chemical changes. Let's dive into the science behind it!
How Does a Candle Work?
Before we explore where the wax goes, let's understand how a candle works. A typical candle consists of three main components: the wick, the wax, and the flame. When you light the wick, the heat of the flame melts the wax near the wick. This liquid wax is then drawn up the wick, where the heat of the flame vaporizes the liquid wax, turning it into a gas. This gas reacts with the oxygen in the air and produces heat, light, water vapor, and carbon dioxide.
What Happens to the Wax?
As the liquid wax is drawn up the wick, it undergoes a process called capillary action. This is the same principle that allows water to move up a plant's roots against gravity. The wick acts as a conduit, pulling the liquid wax upward. Once the liquid wax reaches the flame, it vaporizes and undergoes combustion.
During combustion, the carbon atoms in the wax combine with the oxygen in the air to form carbon dioxide gas (CO2). This is why you may notice a faint smell of burning carbon when a candle is lit. The heat of the flame also causes the surrounding wax to melt, contributing to the continuous supply of liquid wax to the flame.
What About the Solid Wax?
Not all of the wax is vaporized during combustion. Some of it remains in its solid state, forming a pool of melted wax around the base of the wick. This is why you often see a small well of liquid wax in a burning candle. As the liquid wax is drawn up the wick, more solid wax melts to replace it, ensuring a steady supply of fuel for the flame.
Over time, as the candle burns, the solid wax near the wick is gradually consumed. This is why candles eventually burn out and need to be replaced or relit.