Solid State and Crystal Structures

Calcium and strontium crystallizes in face centered cubic structure.

Palladium (Pd) and silver (Ag) crystallise in face centred cubic lattice.

Tantalum (Ta) and tungsten (W) crystallises to form body centred cubic lattice.

It is difficult to break an iron nail because of strong force of attraction.

The space group (or crystallographic group, or fedorov group) of a crystal is a description of the symmetry of the crystal, and can be one of 230 types.

In the hexagonal system, we have an additional axes which gives the crystals six sides. Three of these are equal in length and meet at 60° to each other. The C or vertical axis is at 90° to the shorter axes. Mineralogists sometimes divide this into two systems, the hexagonal and the trigonal, based on their external appearance.

Point defects are defects that occur only at or around a single lattice point. They are not extended in space in any dimension. Strict limits for how small a point defect is, are generally not defined explicitly, but typically these defects involve at most a few extra or missing atoms.

The trigonal crystal system is one of the seven crystal systems. It consists of the five point groups of the seven space groups with a rhombohedral lattice. In the classification into 6 crystal families, the trigonal crystal system is combined with the hexagonal crystal system and grouped into a larger hexagonal family.

In crystallography, the space group of a crystal is a description of the symmetry of the crystal and can have one of 230 types.

Crystallography is the experimental science of the arrangement of atoms in solids. The word crystallography derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.

Orthorhombic crystal system: Unit cell vector lengths a≠ b ≠ c and unit cell vector angles α = β = γ = 90° Tetragonal crystal system: Unit cell vector lengths a = b ≠ c and unit cell vector angles α = β = γ = 90°

For orthorhombic lattice system, possible Bravais lattices are primitive, body centered, face centered and base centered.

Fe₃O₄ and NiFe₂O₄, both are reverse spinels.

Both cyclic silicates as well as chain silicates have the same general formula: (SiO₃)_n^2n-

This option is correct because 'lattice system: edge lengths and axial angles in Monoclinic is a ≠ b ≠ c and α = γ = 90˚, β ≠ 90˚ respectively. in Triclinic, the 'lattice system: edge lengths and axial angles is a ≠ b ≠ c and α ≠ β ≠ γ ≠ 90˚