What two elements were propelled into space after the initial explosion in the Big Bang Theory?

The correct answer is hydrogen and helium. In the aftermath of the Big Bang, which occurred approximately 13.8 billion years ago, the universe rapidly expanded and cooled, leading to the formation of the simplest elements. During the first few minutes, conditions allowed for nuclear fusion to occur, primarily producing hydrogen and helium atoms.

As the universe continued to expand, these light elements served as the building blocks for future star and galaxy formation. The predominance of hydrogen and helium in the observable universe today is a reflection of their origins from this early cosmic event.

The other options, while they involve substances related to the cosmos, do not accurately represent the primary elements formed shortly after the Big Bang. Water and methane, for instance, are more complex molecules resulting from chemical processes that occurred later in the evolution of the universe and require carbon and oxygen. Similarly, planets and stars formed millions of years later from the accumulation of hydrogen and helium, along with heavier elements made in stars. Dust and gas are also later products of star formation rather than direct outputs of the Big Bang. Thus, hydrogen and helium are critical to understanding the early universe and its development.