Acid Rain

                                           pH Scale
Acid gases are produced into the eartrh's atmosphere when fossil fuels such as oil and coal are burned in factories, power stations and even in our own homes! Some of these gases get released into the sky, they then mix with the precipitation in the clouds to cause higher levels of acidic rain.
When this acidic rain falls it can cause alot of damage to trees, bulidings, soils, statues etc. If the acid rain falls into rivers etc, it can kill the fish and dirty the water (several cases of this in Scandinavia). Acid rain can also casue air pollution , when these harmful gases are released, they are then pushed by strong winds to other coutries. Acid rain can also affect the air quality. This endangers us of taking in harmful gases in the air around us.
The level of acidity can be measured on the pH Scale. It ranges from numbers 1-14. The greater the pH number,the more basic the acid is (eg. toothpaste.) The smaller the pH number, the more acidic the acid is (eg. lemon juice.) The more neutral the acid is at number 7 (eg. water.)

Smog is a combination of smoke and fog. When these two come into contact, they create a dusty grey like atmosphere that does not move away easily. When smog is present, it empares peoples' sight and it is hard to breathe.