A planetary nebula is a(n) . Group of answer choices a shell of gas ejected by and expanding away from an extremely hot dying low-mass star a shell of gas ejected by and expanding away from an extremely hot dying high-mass star an expanding atmosphere of a low-mass star as it becomes a red giant a contracting shell of ionized interstellar medium absorbed by a dying low-mass star a contracting shell of dusty material from planets destroyed by a dying low-mass star

Planetary nebular is

A shell of gas ejected by and expanding away from an extremely hot dying high-mass star

An expanding atmosphere of a low-mass star as it becomes a red Giants.

Explanation:

Planetary nebular is a form of nebula emission that comprises an expanding and glowing shell of gas that is ejected from red giant stars.

Planetary nebulae play an important role in the chemical evolution of the Milky Way by expelling elements into the interstellar medium from stars where those elements were produced.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia