Answer:
lacks systematic and regular arrangement of atoms over relatively large atomic distances
Step-by-step explanation:
The major difference between a crystalline substance and an amorphous substance is the arrangement of particles.
In a crystalline material, particles are arranged in a definite and regular repeating manner throughout the solid. This definite pattern of particle arrangement accounts for the unique properties of crystalline substances.
On the other hand, amorphous substances lack this regular arrangement hence their properties differ significantly from those of crystalline substances.