Compare surface, subsurface, and placer mining in terms of damage to the environment.

Surface mining, which is also known as strip mining, is when soil and rock overlaying mineral deposit is removed. It can cause habitat destruction, air pollution from dust particles, soil erosion and pollution. Subsurface mining is removing deposits from the Earth by drilling underneath layers of rock and dirt. To keep the pathways clear, mining companies have to pump out large amounts of water, which go into surface ecosystems. That disrupts the ecosystem by changing the pH conditions of soil and water sources. Placer mining is mining of stream bed deposits for minerals, a way of obtaining minerals and metal resources. Although, because it is small, causes less damage to the surrounding environment it still can disrupt river ecosystems with pollution and sediments. 
 

I hope this helps!!

Gay-lussac's law i think.