431. Molar heat of vaporization of water is_________________?
A. 40.7 KJ/mole
B. 40.7 J/mole
C. 40.7 cal/mole
D. 40.7 Kcal/mole

432. Crystallites are present in_________________?
A. crystalline solids
B. amorphous solids
C. liquid crystals
D. all of the above

433. A malleable solid is one which can be_________________?
A. Converted into wires
B. Converted into thin sheets
C. Melted easily
D. All of the above

434. Crystalline solids can be identified easily from their ___________________?
A. Sharp melting point
B. Definite geometry
C. Transition temperature
D. Colour

435. The viscosity of solids is________________?
A. Infinite
B. Negligible
C. Medium
D. No concept of viscosity in solid

436. Which solids are called true solids _______________?
A. Metallic
B. Amorphous
C. Crystalline
D. Vitreous

437. The number amino acid units for each turn of helix on average are____________________?
A. 21
B. 23
C. 25
D. 27

438. If a physical and chemical change takes place at a constant pressure then the heat change during the process is called__________________?
A. Heat of transition
B. Heat of fusion
C. Enthalpy change
D. All of above

439. The amount of heat absorbed when one mole of a liquid is changed into gas at its boiling point is_____________________?
A. Molar heat of sublimation
B. Molar heat of fusion
C. Molar heat of vapourization
D. Latent heat of that liquid

440. All of the following were theorized by Bohr in his description of the atom except__________________?
A. Angular momentum of electrons in multiples of h/2?
B. Electrons revolve in discrete circular orbits
C. Energy of each electron is directly proportional to n2
D. Electrons radiate energy continuously in a given orbit.