• Soft drink bubbles are due to carbon dioxide, a common acidic oxide.zitronenbrause image by Carmen Steiner from Fotolia.com
  
  In chemistry, a number of compounds called "oxides" exist. An oxide is a compound formed by a single element that combines with oxygen. Oxides come in three varieties: acidic, basic and neutral. Basic oxides react with water to form an alkali, while neutral oxides are insoluble in water, or form neither an acid nor an alkali. Acidic oxides, when combined with water, form acids. Several compounds exist that you may not expect to be acidic oxides, but in fact, are.
  
  

Carbon Dioxide

• Carbon dioxide, or CO2, is a common acidic oxide. C02 is soluble only in water under pressure, and it is commonly kept cold. C02 is an abundant compound, found virtually everywhere on Earth and essential to maintaining plant and animal life. In the human body, C02 works to keep blood pH neutral in the form of carbonic acid. However, C02 can lead to asphyxiation if released in an unventilated area due to a lowering of oxygen concentration in the air. Solid C02 is known to cause frostbite, burns and blisters due to its extremely low temperature. C02 is commonly used for fire extinguishers, dry ice, as an ingredient to the fluid that decaffeinates coffee, in baking powder, and of course, to make soft drinks fizzy.
  
  

Nitrogen Dioxide

• Nitrogen dioxide, or NO2, is a poisonous orange or brown gas known for a particularly foul odor. It is typically generated when a metal, such as copper or silver, is exposed to nitric acid. Exposure can cause human lungs to become irritated, and it can lower natural resistance to respiratory infection. Those suffering from asthma or bronchitis are particularly sensitive to exposure to this compound.
  
  

Sulfur Trioxide

• Sulfur Trioxide, or SO3, is a highly reactive, solid white crystalline compound. When exposed to water, SO3 combines with explosive force and creates sulfuric acid. This acid is highly corrosive and extremely dangerous. S03, when combined with air, creates dense, white fumes of corrosive, poisonous gas. In its solid form, SO3 is corrosive to skin and metal, and it can cause eye and skin burns. It may also cause fire if brought into contact with organic materials such as wood or cotton. S03 must be handled with extreme care to prevent severe injury or death.