UNIT 1 A

Unit -1

2 marks Questions.

1. What is Materials Science?

A. Materials science is a part of engineering that involves discovering and designing new materials and analysing their properties and structure. That information can then be used to make design choices. We can also use our knowledge to break materials apart and recombine them in creative ways. For example, did you know that nylon is created from oil? That kind of thing wouldn't be possible without materials science.

2. When will interstitial solid solution occur?

A. Interstitial solid solution is formed when atoms of small atomic radius ﬁt into the empty spaces or interstices of the lattice structure of the solvent atoms as shown in Fig.

Since the empty spaces of the lattice structure are limited in size, only atoms with atomic radius less than 1 angstrom are likely to form interstitial solid solutions.

3. What is the difference between Schottky and Frenkel defect?

Schottky Defect	Frenkel Defect
1. Equal number of cations and anions are missing from the lattice sites. 2. Found in highly ionic compounds with high coordination numbers and where the cations and anions are of similar size. 3. Density of the solid decreases Examples: KBr, NaCl KCI	1. A cation leaves the normal lattice site and occupies an interstitial site. 2. Found in ionic compounds with low coordination numbers and where the anions are much larger in size than cations. 3. Density of the solid remains the same. Examples:Zns, AgBr