Explanation:
ABC looks like the metamorphic rocks are more usable than other rocks
In order to <span>complete and balance the following reactions, you should add a Fe into it. So it will look like uo2+ +cr o^2- 7 ـــــــــــــــــــــ uo2+ +cr3+Fe. The answer to the following given statement or missing answer is Fe. </span>
The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it. Aluminium oxide has a very high melting point (over 2000°C) so it would be expensive to melt it. The use of cryolite reduces some of the energy costs involved in extracting aluminium.
Sorry it’s a bit blurry, you should be able to make it out