What are the two lightest elements primarily composing the Interstellar Medium?
Answer
Hydrogen and Helium
The vast space between star systems, known as the Interstellar Medium (ISM), is fundamentally permeated by gas. This gas is overwhelmingly composed of the two lightest elements created in the early universe: hydrogen, which is the most abundant, and helium. Although the ISM is a mixture of various elements and phases, hydrogen and helium constitute the vast majority of its mass and particle count, providing the raw material for subsequent cosmic structures.
Related Questions
What are the two lightest elements primarily composing the Interstellar Medium?What chemical state does hydrogen adopt within the coldest and densest molecular clouds?Which molecule acts as a proxy tracer for observationally silent molecular hydrogen in cold clouds?What outward force must balance the inward pull of gravity to maintain a gas cloud's stability?What critical threshold describes when gravity begins to dominate internal pressure in a collapsing cloud?Why are cold gas clouds often seen as dark patches against brighter backgrounds?What substances compose the tiny solid particles, known as dust, existing within gas clouds?How large can giant molecular clouds extend, and what is their typical mass comparison?What process causes gravitational collapse in a gas cloud leading to star birth?What dynamic mechanism is suggested by observations of gas clouds escaping the central region of the Milky Way?