In the revised Nebular Hypothesis, which of the following was NOT considered a major constituent of the primordial solar nebula?

The correct option is Oxygen.

Explanation

The Nebular Hypothesis, originally proposed by Immanuel Kant and later revised by Laplace, is a primary theory regarding the origin of the solar system. In 1950, Otto Schmidt (Russia) and Carl Weizsacker (Germany) revised this hypothesis to explain the formation of planets through physical processes within a solar nebula.

Analysis of Constituents:

• Hydrogen and Helium: The revised hypothesis posited that the sun was surrounded by a solar nebula containing mostly Hydrogen and Helium. These were considered the primary gaseous components of the primordial cloud.
• Dust: The hypothesis explicitly stated that alongside these gases, the nebula contained what may be termed as dust. The friction and collision of these dust particles were crucial for the formation of a disk-shaped cloud and the subsequent accretion of planets.
• Oxygen: While oxygen is a common element in the universe, the specific definition of the primordial solar nebula in the revised Nebular Hypothesis lists Hydrogen, Helium, and Dust as the major constituents. Oxygen was not categorized as a distinct major constituent in this theoretical framework compared to the dominance of Hydrogen and Helium gases.

Key Takeaway:
The revised Nebular Hypothesis by Schmidt and Weizsacker characterizes the primordial solar nebula as being composed primarily of Hydrogen, Helium, and Dust.