Which ingredients made up about 98% of the solar nebula?
(a) rock and metal
(b) hydrogen compounds
(c) hydrogen and helium
The correct answer and explanation is :
The correct answer is (c) hydrogen and helium.
Explanation:
The solar nebula, which is the cloud of gas and dust that eventually condensed to form the Sun and the rest of the solar system, was primarily composed of hydrogen and helium. These two elements made up about 98% of the nebula’s mass. This is because hydrogen and helium are the most abundant elements in the universe, and they were present in large quantities at the time of the formation of our solar system.
Hydrogen (H) is the most abundant element in the universe, making up about 75% of the mass of the solar nebula. This element is the primary fuel for nuclear fusion, which powers stars like our Sun. Helium (He), the second most abundant element, made up about 24% of the mass of the nebula. These two elements are light gases that were formed in the early stages of the universe during the Big Bang.
In addition to hydrogen and helium, the solar nebula contained trace amounts of other elements, such as oxygen, carbon, nitrogen, and various metals, but these only made up a small fraction of the total mass. The heavier elements, including rock and metal (option a), and hydrogen compounds like water (option b), were far less abundant.
The dominance of hydrogen and helium in the solar nebula can be attributed to the conditions of the early universe. Shortly after the Big Bang, the universe was predominantly hydrogen and helium, and this composition was preserved in the material that formed the solar nebula. As the nebula collapsed under gravity, it eventually led to the formation of the Sun and the planets, with the majority of the material remaining in the Sun, which is primarily composed of hydrogen and helium.
Thus, hydrogen and helium are the key ingredients that made up about 98% of the solar nebula.