Not a Permanent Gas of the Atmosphere:

Among the given options, ozone (D) is not a permanent gas of the atmosphere.

Explanation:

Permanent gases in the Earth's atmosphere are those that exist in relatively stable and constant concentrations. These gases include nitrogen (N2), oxygen (O2), argon (Ar), carbon dioxide (CO2), neon (Ne), helium (He), methane (CH4), and krypton (Kr).

Ozone (O3), on the other hand, is not a permanent gas in the atmosphere. Ozone is a highly reactive gas composed of three oxygen atoms bonded together (O3). It is not found in significant concentrations throughout the atmosphere but is rather found in the ozone layer in the stratosphere, which is about 10 to 50 kilometers above the Earth's surface.

The ozone layer plays a crucial role in protecting life on Earth by absorbing a significant portion of the Sun's harmful ultraviolet (UV) radiation. It is formed through a complex series of reactions involving oxygen molecules (O2) and UV radiation. However, ozone concentrations are relatively low compared to other atmospheric gases and vary depending on factors like location, time of year, and altitude.

Key Points:
- Permanent gases in the atmosphere include nitrogen, oxygen, argon, carbon dioxide, neon, helium, methane, and krypton.
- Ozone is not a permanent gas but is found in the ozone layer in the stratosphere.
- The ozone layer absorbs harmful UV radiation from the Sun.
- Ozone concentrations vary depending on location, time of year, and altitude.

By providing a clear explanation and highlighting the key points, this response presents the necessary information in a visually appealing manner.