What is mercury deposition?

Question

I need to know this to do a project for earth's atmosphere?

Answer 1

An example: mercury is present as a trace element in coal. When coal is burned, the mercury (Hg) turns to a gas. As the gas cools, the mercury turns back to a solid and attaches itself to the fly ash. These fine particles, with Hg attached, fall out onto soil or surface water, so Hg enters the environment and can be taken up into the food chains.

Answer 2

See here:

http://www.we-energies.com/environment/mercury_qa.htm