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%

Explanation:

Step1: Calculate mined amount

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

Step2: Compare recycled and mined amounts

Iron & Steel: Recycled (\(52500000\)) < Mined (\(53500000\)).
Aluminum: Recycled (\(3380000\)) < Mined (\(3740000\)).
Copper: Recycled (\(805000\)) < Mined (\(1645000\)).
Lead: Recycled (\(1050000\)) > Mined (\(490000\)).
Zinc: Recycled (\(198000\)) < Mined (\(882000\)).

Answer:

Lead