Potato Candle Demo

In this demonstration, a peeled potato is cut into the form of a candle and an almond slice is used as the candle’s “wick.” The teacher lights the almond slice on fire and it burns. The students see the object, and make observations about it. Continue reading

Teacher Demo/Student Activity: Powder Disaster

Introduction

Flour is an ingredient that is found in most kitchens and used regularly for baking and cooking.  Consequently, it is considered safe, and people do not regard the potential hazards.  In reality, flour and dust explosions are extremely dangerous, and reducing the risk of such an explosion is a major concern to the agriculture and food processing industries.

The purpose of this demonstration/activity is to illustrate the importance of being aware of potentially harmful situations and practices in the workplace. In particular, the dustiness of a material can affect the nature of chemical reaction, affecting a safe working environment.

How does it work?

Flour is combustible. When sitting as a stable pile the fuel (flour) is more connected to other flour particles than oxygen particles. As dust, each dust particle is surrounded by oxygen particles. This supports the combustion of the flour particle. As each particle moves through the flame, the combustion moves with the particles. Flour explosions tend to be connected to the movement of flour through air. The source of ignition is often discovered to be a static discharge.

 

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5 weird ways to put out a candle

What happens when you pour liquid nitrogen on a flame? What about when you blow on the flame with a cup in the way? Try these five unusual ways to extinguish a candle. Pour out the flame with CO2. Cut off the oxygen supply to the flame without fully covering it. Snuff out the flame with a coil of copper wire, and when it appears dead, it will amazingly come back to life!

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Canada Q&A: Can you light a match on the moon? A quick study of the science of fire

The Globe and Mail’s science reporter, Ivan Semeniuk, explains how fire works in space. This video is a part of a series called, Canada Q&A: Globe journalists answer your questions – from wine to politics to sports and everything in between