Metallic bonds are responsible for many properties of metals, such as conductivity. Why is this possible?

In metallic bonding, the valence electrons are free to move throughout the metal structure. This accounts for many of the properties of metals. The mobile electrons can act as charge carriers in the conduction of electricity and as energy carriers in the conduction of heat.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.