Which term denotes an imperfection or deviation from the ideal crystal lattice?

Which term denotes an imperfection or deviation from the ideal crystal lattice?

• A. Crystal Axes
• B. Crystal Planes
• C. Glide Plane
• D. Defect

Answer: (D)

Imperfections in a crystal lattice are called defects. An ideal lattice would be perfectly periodic, but any deviation—such as missing atoms (vacancies), extra atoms in interstitial sites, or impurity substitutions—counts as a defect. The other terms describe regular lattice features: crystal axes are the directions that define the geometry, crystal planes are the flat layers of atoms, and a glide plane is a symmetry element that combines reflection with translation. So the term for an imperfection or deviation from the ideal lattice is defect.

Imperfections in a crystal lattice are called defects. An ideal lattice would be perfectly periodic, but any deviation—such as missing atoms (vacancies), extra atoms in interstitial sites, or impurity substitutions—counts as a defect. The other terms describe regular lattice features: crystal axes are the directions that define the geometry, crystal planes are the flat layers of atoms, and a glide plane is a symmetry element that combines reflection with translation. So the term for an imperfection or deviation from the ideal lattice is defect.