Some common gases.

Hydrogen, oxygen and carbon dioxide .
Carbon dioxide is a very important gas. We use it in our cooking and in our soft drinks. Carbon dioxide is also used in fire extinguishers. You can make carbon dioxide in your kitchen. Mixing vinegar and baking powder will cause a chemical reaction to happen during which carbon dioxide is produced. The fizzy nature of some of the drinks drinks that you take when you have an upset stomach is due to the production of carbon dioxide.
Carbon dioxide is heavier than air and can be poured from a glass onto a fire to extinguish it. Click to see 120kb video.
One way to identify carbon dioxide is to place a burning match in the container. If the flame goes out then most likely carbon dioxide gas is present. Click to see a 120kb video.

Oxygen gas, like carbon dioxide, is a colourless, odorless gas that supports combustion. In other words oxygen supports burning. Without oxygen there would be no fires. Oxygen can be identified by placing a glowing, red hot candle wick in the container. If the wick erupts into flames then oxygen gas is most likely present. Click to see a 300kb video.

Oxygen is also responsible for the rusting of metals. Rusting can be greatly increased by heating the metal before placing it in pure oxygen. Click to see a 120kb video and note the amount of heat released by the rusting process.
Hydrogen is also odorless and colourless. Unlike carbon dioxide, hydrogen gas is lighter than air and was used extensively in the early 1900s in giant airships. However, hydrogen gas is very explosive. It can be identified by placing a burning match into the container. A small "POP" is heard with the production of a small flame. This is called the "POP" test. Click to see a 120kb video.

Invetigation.

Yeast are a fungus that are used in bread making. Why are yeast used to make bread? Click for more information.

A candle that burns in a sealed bottle soon goes out. Why?
Firemen say never to open doors and windows when a fire is burning fiercely inside a room. Does this make sense? What are we trying to keep away from the fire by keeping the doors and windows closed ?

 

What was the Hindenberg disaster? What gas was responsible? Why was this gas used in the first place?

Where else is hydrogen used? Click