Q: If Germanium crystallises in the same way as diamond, then which of the following statement is not correct?

Explanation:

Germanium atom: Diamond Structure

In the diamond structure, each germanium atom is arranged in a tetrahedral geometry, meaning every atom is bonded to four neighboring atoms. This arrangement leads to a highly symmetrical and stable crystal lattice.

Let’s examine each statement:

Option A: Every atom in the structure is tetrahedrally bonded to 4 atoms.
– This is correct. In the diamond structure, each germanium atom forms four covalent bonds with neighboring atoms, creating a tetrahedral geometry.

Option B: Unit cell consists of 8 Ge atoms and coordination number is 4.
– This is also correct. The conventional unit cell for the diamond structure contains eight germanium atoms, and each atom has a coordination number of four, meaning it is connected to four other atoms.

Option C: All the octahedral voids are occupied.
– This statement is not correct. In the diamond structure, while octahedral voids exist within the lattice, they are not all occupied by atoms. The structure primarily involves tetrahedral bonding, and the octahedral sites remain unfilled or only partially filled depending on the specific structure.

Option D: All the octahedral voids and 50% tetrahedral voids remain unoccupied.
– This is correct. In the diamond structure, not all the available octahedral voids are occupied by atoms. Additionally, only half of the tetrahedral voids are typically filled, aligning with the tetrahedral bonding nature of the structure.

Therefore, the incorrect statement is that all the octahedral voids are occupied in the diamond-like germanium crystal structure.