What evidence tells you that chemical and physical changes take place in a candle as it burns?

What evidence tells you that chemical and physical changes take place in a candle as it burns?

Burning a candle shows both physical and chemical changes by transforming the shape of the candle and by oxygen fueling the flame and releasing carbon dioxide in the process.

What is the evidence for a chemical reaction when a candle burns?

All the light a candle makes comes from a chemical reaction known as combustion in which the wax (made from carbon-based chemicals typically derived from petroleum) reacts with oxygen in the air to make a colorless gas called carbon dioxide. Water is also produced in the form of steam.

Why is the candle flame extinguished after a few seconds?

Carbon dioxide molecules are heavier than air. Because of this, they push the oxygen and other molecules in the air out of the way as they sink down over the flame and candle. When oxygen is pushed away from the wick, it can’t react with the wax anymore. This makes the flame go out.

Is burning a physical change or a chemical change why?

The process of burning (as opposed to evaporating) is a chemical reaction, a chemical change. The wax molecules are undergoing a chemical change; they are changing into different molecules by reacting with a substance in the air.

Why do Yankee candles go black?

When you have been burning a candle for a while and begin to notice that there is black creeping up the sides of the jar, this is carbon in action. Flames produce carbon and the bigger the flame, the more carbon there is. The black that you see in the jar is due to a lack of oxygen.

What happens when you pour water on a burning candle?

The National Candle Association recommends using a candle snuffer or some sort of lid to extinguish a candle. The organization says using water can cause hot wax to splatter, which is one way an explosion can occur.

How does a burning candle show both physical and chemical changes?

The physical change is quite obvious and in fact, it can be seen. When the candle burns, the wax slowly melts and the candle gets smaller and smaller. This wax, as can be seen, will drip onto the candle and stick to it. When this wax forms back into a solid and stays on the candle, that is another physical change that can occur.

How does the wax of a candle change?

Physical Changes in Burning Candle: On heating, candle wax melts and form liquid wax. It is a physical change. Since it again turns into solid wax on cooling. This is a reversible change.

When does wax melt it is a physical change?

Wax melts when energy (heat)is supplied to it and hence it is physical change. Also, the burning of wax is an exothermic reaction as it gives out energy and CO2 which is a chemical reaction.

What happens to liquid wax when it is burned?

The liquid wax vaporizes due the heat produced by the flame. This wax vapor near to flame burns and gives new substances like Carbon Dioxide, Carbon soot, water vapours, heat and light. This is an irreversible change.