What type of defect can arise when a solid is heated? Which physical property is effected by it and in what way?

Q 1.19: What type of defect can arise when a solid is heated? Which physical property is effected by it and in what way?

Solution:

On heating, some atoms or ions leave the lattice site completely so vacancy defect can arise. A solid will show vacancy defect when some of the lattice sites are vacant. Vacancy defect always decreases the density of the solid.