Silicates are the most common mineral group and differences ...

[penza]

Silicates are the most common mineral group and differences between some silicates are due to only slight variations in their compositions. Explain the conditions necessary for elements to substitute to occur for Si and Mg.
 
  What will be an ideal response?

Question 2

Recycling aluminum is particularly beneficial because it
 
  A) saves energy.
  B) creates jobs in the country that recycles.
  C) decreases the need to import virgin aluminum ore.
  D) saves energy, creates jobs, and decreases imports of virgin aluminum ore.

[komodo7]

Answer to Question 1

Substitution of one element must be of comparable size to fit into the same site in crystal structure.
Al3+ swaps for Si4+ in silicate tetrahedron.
Charge differences must be accommodated.
Add other cations (positive charges); no longer quartz.
Mg2+ and Fe2+ are similar size and charge and swap readily in minerals such as olivine.

Answer to Question 2

D

[penza]

Thanks for the timely response, appreciate it

[helenmarkerine]

Excellent