Solid State Chemistry and Crystal Structures

Orthorhombic crystals have four space lattices with body centred rectangular prism arrangement.

Edge length of the NaCl crystal = 2 x distance between Na⁺ and Cl^- ions
= 2 x 265 = 530 pm
Now, for face centred cubic unit cell,
a√2 = 4r
r = a√2 / 4 = 530 x 1.414/4 = 187.35 pm.
Hence, the apparent radius of NaCl crystal is 187.35 pm.

Li, Na and K all have body centred cubic structure.

Both silver as well as gold metals are extracted from cyanide process only.

H₂O (ice) and CO₂ (solid) both are the examples of molecular crystals.

The extraction of lead from its ore is done through various processes such as crushing and concentration through a froth flotation process.

When potential difference is applied to mobile electrons, they conduct electric current. In this case the energy band gap is very low or zero, hence such type of molecules are called metallic or good conductors to electricity (like - VO, TiO, CrO₂, etc.). If the energy band gap is  more than that of metallic conductors they are reffered to as semiconductor, i.e., FeO, V₂O₅, Mn₂O₃, CuO, etc. If the energy band gap is very large, the molecules are called as insulators like - MnO.
Hence, V₂O₅ and Mn₂O₃ are both categorized as semiconductors.

Both NaNO₃ and CaCO₃ have rhombohedral (a = b = c and a = b = g ≠ 90^o) structure.

Oxidation state of iron metal in siderite (FeCO₃) is + 2.
Hence, siderite, an ore of iron has the lowest oxidation state for iron as central atom.

Mg, Zn, Mo and V all represent hexagonal close packed structure.

For face centred cubic unit cell,
a√2 = 4r
r = 361 x 1.414/4
r = 127.6 pm
Hence, the apparent radius of the element ‘X’ will be 127.6 pm.

Cytochrome oxidase metalloenzyme contains copper. Cytochrome oxidase is a metalloenzyme containing copper and a porphyrin, found in mitochondria and important in cell respiration as an agent of electron transfer from certain cytochrome molecules to oxygen molecules.

CsCl has permitted coordination number of 8 with cubic arrangement.