Answer:
The answer is 3.89x10^-8
Explanation:
The term vacant is used in crystallography to indicate a defect in a crystal. The crystals naturally have imperfections. A defect in which an atom is missing is called a vacancy defect, or Schottky's defect.
The temperature depends of the vacancy density, we have:
NV/N = A*e^-(ΔHv/R*T) = 1.1*e^(-100000/(8.314*701)) = 3.89x10^-8