Below you will find some simple experiments involving oxygen. Looking fo casino bonuses ? Try No Deposit Bonus at Maple Leaf. Everything you looked for is here! They will help you understand how oxygen combines with other substances on Earth.
Oxygen is the most common element in the Earth’s crust, comprising about half of the crust. It is the second most common element in the Earth’s atmosphere, after nitrogen, and makes up almost one quarter of the atmosphere. Most of the Earth’s surface is covered in water, which is made of hydrogen and oxygen.
Because oxygen is highly reactive, in addition to being extremely abundant, many compounds on Earth consist of oxygen and at least one other element.
In fact, oxygen is so reactive, that if it were not for living organisms, such as algae, producing free oxygen via photosynthesis, there would be hardly any free oxygen in the air at all. Almost all of the oxygen on Earth would exist in chemical compounds with other substances. This situation existed early in the Earth’s history, before photosynthesis evolved. Then, the atmosphere had almost no free oxygen, and the earliest living things on Earth were anaerobic – they did not need oxygen to survive.
Oxides, compounds that contain oxygen at least one other element, comprise the most abundant minerals on the Earth’s crust. The most common of these are compounds containing silicon and oxygen and compounds containing aluminum and oxygen.
The rate at which oxygen combines with another substance can vary.
When oxygen combines with other metals slowly, the process is known as corrosion.
Rust, or iron oxide, is formed when oxygen combines with elemental iron.
When oxygen and another substance combine at a rapid rate, we perceive this as burning, or combustion.
Rust Requires Oxygen
This experiment will show that when things rust, oxygen takes part in the process.
Equipment Needed
Steel Wool
1 pencil
1 rubber band
1 large mug or cup, tall enough for a pencil to fit inside it
2 shallow bowls of water with flat bottoms - both should be filled to the same level
The Experiment
Moisten some steel wool.
Use the rubber band to fasten the steel wool to the top of the pencil.
Place the pencil and the steel wool in the cup, and then place the cup upside down in one of the bowls of water.
Mark the side of the cup to show the water level.
Place the second bowl of water next to the first.
Leave everything for a few days. Then go back and look at your experiment.
When you examine the bowl which contains the cup with the steel wool,you will see that the steel wool has begun to rust and that the level of water inside the cup has risen, so that the water inside the cup is higher than the water outside the cup.
This is because when the steel wool rusts, it combines with oxygen from the air. As oxygen is removed from the air, the air pressure around the steel wool decreases. The air outside the cup forces the water up to offset the area of low pressure inside the cup.
Of course, some of the water in the bowl may have evaporated, which would have caused the water level outside the cup to decrease. You can check how much of this decrease was the result of rusting and how much was caused by evaporation by comparing the water level in both bowls.
Relighting a Candle
When you light a candle, gas from the melting wax combines with the oxygen in the air to create a flame.
The smoke that is produced will contain chemicals from the wax, which will also burn.
You can use this smoke to relight the candle.
Equipment Needed
1 candle
Matches or a lighter
The Experiment
Light the candle then blow it out.
Before the smoke dissipates, hold the flame from a match or a lighter to the top of the stream of smoke.
The flame will leap down the smoke and ignite the wick again.