Which of the following changes did not occur during the collapse of the solar nebula?
(a) spinning faster
(b) heating up
(c) concentrating denser materials nearer the Sun
The correct answer and explanation is :
The correct answer is: (c) concentrating denser materials nearer the Sun.
Explanation:
The collapse of the solar nebula refers to the process that led to the formation of the solar system. A nebula, which is a vast cloud of gas and dust, collapsed under its own gravity, eventually forming the Sun and the planets. This process is critical for understanding the early stages of the solar system’s formation.
Now, let’s break down the changes that occurred during this collapse:
- Spinning faster (a): As the solar nebula collapsed due to gravity, its angular momentum was conserved. The nebula started as a large, diffuse cloud, but as it collapsed, it began to spin faster. This phenomenon is similar to how a figure skater spins faster when they pull in their arms. The conservation of angular momentum is a key principle in astrophysics, and it led to the formation of a rotating disk of material, which later formed the Sun and the planets.
- Heating up (b): As the nebula collapsed, the particles within it moved closer together and their gravitational potential energy was converted into kinetic energy, which caused the material to heat up. This heating effect was crucial because it eventually led to the formation of the Sun. The core of the collapsing nebula became hot enough to initiate nuclear fusion, forming the Sun. Additionally, the increased heat from the collapse contributed to the temperature gradients that shaped the solar system, with hotter regions closer to the Sun and cooler regions further away.
- Concentrating denser materials nearer the Sun (c): This statement is not correct. While denser materials did indeed play a role in the formation of planets, the process during the collapse of the solar nebula did not directly lead to denser materials concentrating nearer the Sun in a simple way. Instead, the distribution of materials in the nebula was influenced by temperature. The Sun’s intense heat caused volatile materials (like water, methane, and ammonia) to vaporize near the Sun, while only heavier, less volatile materials (like metals and rock) could condense and form solid bodies in the inner part of the solar system. This is the basis for the differentiation between the inner rocky planets (Mercury, Venus, Earth, Mars) and the outer gas giants (Jupiter, Saturn, etc.).
Therefore, while denser materials ended up in the inner solar system, this occurred due to temperature gradients rather than a direct concentration of denser materials near the Sun. Thus, (c) concentrating denser materials nearer the Sun did not directly result from the collapse itself, but from the temperature gradient that followed.