Which of the following is not a point defect?
A
Vacancy
B
Interstitial atom
C
Impurity atom
D
Dislocation
Correct Answer: Dislocation
When the deviation from the periodic arrangement of the lattice is localized to the vicinity of only a few atoms or single atom, it is called a point defect, or point imperfection. The vacancy, interstitial atom, impurity atoms are only single lattice point defects. But dislocation is line defect.