Ques. 1AIPMT 2000
The cations and anions are arranged in alternate form in
- metallic crystal
- ionic crystal
- covalent crystal
- semi-conductor crystal
Answer
(2) ionic crystal
Solution
In an ionic crystal (e.g. NaCl), the constituent particles are positive and negative ions.
⇒ Each cation is surrounded by anions and each anion by cations, so the ions alternate in the lattice and are held by electrostatic attraction.
∴ Metallic crystals contain positive kernels in a sea of electrons, and covalent / semiconductor crystals contain atoms joined by covalent bonds.
Answer: (2)