- The pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at higher temperature turbidity completely disappears. The behavviour is a characteristic of substance forming.
- a. Allotropic crystals
- b. Liquid crystals
- c. Isomeric crystals
- d. Isomorphous crystals
Ans: b. Liquid crystals on heating first become turbid and then on further heating turbidity completely disappears.
2. Glass is a
- a. Liquid
- b. Solid
- c. supercooled liquid
- d. transparent organic polymer
Ans : c. Glass is a supercooled liquid which forms a non-crystalline solid without a regular lattice.
3. Most crystals show good cleavage because their atoms, ions or molecules are
- a. Weakly bonded together
- b. Strongly bonded together
- c. Sperically symmetrical
- d. arranged in planes
Ans : d. crystals show good cleavage because their constituent particle are arranged in plane
4. The ability of a substance to assume two or more crystalline structures is called
- a. Isomerism
- b. Polymorphism
- c. Isomorphism
- d. amorphism
Ans: The phenomenon of the existence of a substance in two or more crystalline structures is called polymorphism.
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