Question

What is the movement of the block of atoms along certain crystallographic plane and directions?

Answer 1

The process by which plastic deformation is produced by dislocation is known as slip.

The crystallographic plane along which the dislocation line crosses is known as slip plane.

Crystallographic plane :

Any set of parallel and equally spaced planes that may be supposed to pass through the centers of atoms in crystals.

From the information above :

The movement of the block of atoms along certain crystallographic plane and directions is known as slip.