Question

Please give me the reasons of the solution!

1. As a polymer becomes more crystalline, ________. A) its melting point decreases B) its density decreases C) its stiffness decreases D) its yield stress decreases E) None of the above is correct.
.2. In the smectic A liquid-crystalline phase, ________.
A) the molecules are aligned along their long axes, with no ordering with respect to the ends of the molecules
B) the molecules are arranged in sheets, with their long axes parallel and their ends aligned as well
C) the molecules are aligned with their long axes tilted with respect to a line perpendicular to the plane in which the molecules are stacked
D) disk-shaped molecules are aligned through a stacking of the disks in layers
E) the molecules are oriented in a totally random fashion

3. For a substitutional alloy to form, the two metals combined must have similar ________. A) ionization potential and electron affinity.
B

Answer 1

1. The answer is option E, that is None of the above is correct.

As a polymer becomes more crystalline,

its melting point doesn't decreases, its density doesn't decreases, its stiffness doesn't decreases and its yield stress doesn't decreases.

2. The answer is option B, that is the molecules are arranged in sheets, with their long axes parallel and their ends aligned as well.

In the smectic A liquid-crystalline phase, molecules are arranged in sheets, with their long axes parallel and their ends aligned as well.

3. For a substitutional alloy to form, the two metals combined must have similar atomic radii and chemical bonding properties.