Which atmospheric layer is represented by F? What are its characteristics?

Ionosphere.

Explanation:

The atmospheric layer that is represented by F is known as IONOSPHERE.

The characteristics of Ionosphere

1. It is considered to be located in the upper layer of the earth's atmosphere due to the location of region F.

2. It is ionized by solar radiation that contains an electrical charge.

3. It functions as a reflector. This can be observed in radio waves broadcasting.

the role of the microscope world in creating new materials .

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.