Question 1
A material is made from Al, Ga, and As. The mole fraction of each element is 0.25, 0.26, and 0.49, respectively. This material would be:
◦
a metallic conductor because Al is present.◦
an insulator.◦
a p-type semiconductor.◦
an n-type semiconductor.◦
none of these are correct.Question 2
A salt, MY, crystallizes in a body-centered cubic structure with a Y– anion at each cube corner and an M+ cation at the cube center. Assuming that the Y– anions touch each other and the M+ cation at the center, and the radius of Y– is 1.50 × 102 pm, the radius of M+ is:
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62.0 pm◦
110 pm◦
124 pm◦
220 pm◦
None of these are correct