Question

Most of the interstellar gas is made up of these two elements. Also give me the percentages of their respective quantities.

a) Hydrogen (75%), Helium (25%)
b) Oxygen (50%), Carbon (50%)
c) Nitrogen (78%), Oxygen (21%)
d) Silicon (30%), Iron (70%)

Answer 1

The interstellar gas primarily consists of hydrogen (75%) and helium (25%), totaling between 96% to 99% of the interstellar gas mass.

Step-by-step explanation:

The interstellar medium, which comprises the material between the stars in galaxies, mostly consists of gases, with hydrogen and helium being the most abundant elements. Observations and studies of stellar spectra reveal that approximately 75% of the interstellar gas is hydrogen, and helium constitutes about 25%. This implies that the correct answer to the student's question is 'a) Hydrogen (75%), Helium (25%)'. Most of the matter within the interstellar space is found in the form of atomic hydrogen, while helium is the second-most abundant element. Together, hydrogen and helium account for between 96% to 99% of the mass of interstellar gas.