Question

mining is the extraction of minerals and metals from earth. while mining produces many products of importance to us, there are also many environmental impacts caused by mining such as erosion, air and water pollution, land and habitat destruction, as well as physical health risks to mine workers.
there are a limited amount of minerals that are available, and thus, recycling is a significant source of metals that can reduce the need for new metal mines. a balance must exist between mining and recycling of important metals and minerals. according to the data provided below, which metal is provided in larger quantities by recycling than by mining?
amount of recycled metal (metric tons) total u.s. supply (metric tons) percent of u.s. supply
iron & steel 52,500,000 106,000,000 50%
aluminum 3,380,000 7,120,000 47%
copper 805,000 2,450,000 33%
lead 1,050,000 1,540,000 68%
zinc 198,000 1,080,000 18%
data source: u.s. geological survey
lead
aluminum
iron
copper

Explanation:

Step1: Calculate mined amount for each metal

Mined amount = Total U.S. Supply - Amount of Recycled Metal
For Iron & Steel: $106000000 - 52500000=53500000$
For Aluminum: $7120000 - 3380000 = 3740000$
For Copper: $2450000 - 805000=1645000$
For Lead: $1540000 - 1050000 = 490000$
For Zinc: $1080000 - 198000=882000$

Step2: Compare recycled and mined amounts

We see that for Lead, the amount of recycled metal ($1050000$ metric tons) is greater than the amount of mined metal ($490000$ metric tons). For other metals, the mined amount is greater than the recycled amount.

Answer:

Lead