- #1
Prashasti
- 63
- 2
Why is the coordination number for fcc 12, but that in NaCl 6? NaCl crystallises in ccp (or fcc) lattice, then how is it possible?
The coordination number for fcc (face-centered cubic) structure is 12. This means that each atom in the structure is surrounded by 12 nearest neighboring atoms.
The coordination number for NaCl (sodium chloride) structure is 6. This means that each sodium ion is surrounded by 6 chlorine ions and vice versa.
The coordination number can be determined experimentally by various techniques such as X-ray crystallography, neutron diffraction, and scanning tunneling microscopy. These techniques allow for the visualization of the arrangement of atoms in a crystal lattice, thereby determining the coordination number.
The coordination number can affect the properties of a material in various ways. For example, a higher coordination number can result in a denser and stronger material. It can also affect the electrical and thermal conductivity, as well as the melting point of a material.
Yes, the coordination number can change for a material under certain conditions. For example, in some solid-state reactions, the coordination number of atoms can change, leading to the formation of a different crystal structure. Additionally, the coordination number can also change under high pressure or temperature conditions.