Why is there an abundance of hydrogen and helium in space?

The 73\% hydrogen and 25\% helium abundances that exists throughout the universe today comes from that condensation period during the first three minutes. The 2\% of nuclei more massive than helium present in the universe today were created later in stars.

How much of the universe does hydrogen and helium make up?

Together, helium and hydrogen make up 99.9 percent of known matter in the universe, according to Encyclopedia.com.

Why do you think hydrogen and helium were the first to show up?

Within about 3 minutes after the Big Bang, conditions cooled enough for these protons and neutrons to form hydrogen nuclei. This is when recombination occurred — neutral hydrogen (and helium) finally appeared because they could “recombine with” (hold on to) electrons without easily losing them to stray radiation.

Why is hydrogen the most abundant element?

Why is hydrogen the most abundant element in the universe? Hydrogen has one proton, one electron and is the only element with no neutrons, making it the simplest element in the universe. Because of this, Hydrogen is believed to be the most abundant element, accounting for about 90\% of the visible universe.

What is hydrogen gas made up of?

Hydrogen production is the family of industrial methods for generating hydrogen gas. As of 2020, the majority of hydrogen (∼95\%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of heavier hydrocarbons, and coal gasification.

What are they each made of hydrogen and helium?

Stars are made of very hot gas. This gas is mostly hydrogen and helium, which are the two lightest elements. Stars shine by burning hydrogen into helium in their cores, and later in their lives create heavier elements.

What percentage of the universe is made up of heavy elements?

Hydrogen and helium are estimated to make up roughly 74\% and 24\% of all baryonic matter in the universe respectively. Despite comprising only a very small fraction of the universe, the remaining “heavy elements” can greatly influence astronomical phenomena. Only about 2\% (by mass) of the Milky Way galaxy ‘s disk is composed of heavy elements.

What is the mass-fraction of hydrogen and helium in the universe?

As another example, looking at the mass-fraction abundance of hydrogen and helium in both the Universe as a whole and in the atmospheres of gas-giant planets such as Jupiter, it is 74\% for hydrogen and 23–25\% for helium; while the (atomic) mole-fraction for hydrogen is 92\%, and for helium is 8\%, in these environments.

What is the abundance of chemical elements in the universe?

Abundance of the chemical elements. As another example, looking at the mass-fraction abundance of hydrogen and helium in both the Universe as a whole and in the atmospheres of gas-giant planets such as Jupiter, it is 74\% for hydrogen and 23–25\% for helium; while the (atomic) mole-fraction for hydrogen is 92\%, and for helium is 8\%,…

How much of the universe is made up of matter?

The elements – that is, ordinary (baryonic) matter made out of protons and neutrons (as well as electrons) – are only a small part of the content of the Universe. Cosmological observations suggest that only 4.6\% of the universe comprises the visible baryonic matter which constitutes stars, planets and living beings.