All naturally occurring elements has their origins in the stars.
In the before approximately 13.7 billion years ago all of the known energy and matters in the universe was concentrated in a single dense region of space known as the ylem and having temperature about 10¹³ kelvin.
There's no walls to contain it. The ylem is exploded in a cosmic genesis event known as the Big Bang, and the universe has been expanding ever since.
There's a variety of proof supporting the theory of Big Bang. The electronic spectra from the distant galaxies had been sown to Doppler-Shifted to the red shifting is longer wavelength and it is indicated that they are moving away from our solar system.
The magnitude of the red shift, the age of the universe can be calculate to be approximately 13.5- 13.9 billion years. There is exists universal cosmic and microwaves background radiation from every corner of the universe is believed to be the remnant of the initial Big Bang events that has a block- body radiation of the exact temperature 2.725. The ratio of Helium and Hydrogen in the universe is essentially constant at 0.23 and there's little difference in the isotopic rations of these two chemical elements across the entire universe, this is indicated that majority of the Helium and Hydrogen was created as a result of a single cosmic event. The evolution of the universe had taken place in all stages. The 1st stage is following the Big Bang was the created by the elementary particles. Firstly energy and matters existed in a sort of cosmic soup and they could easily interconvert with one another. The universe is expanded it to cool to temperature between 10¹⁰ and 10¹² kelvin and the first protons and neutrons were formed.
The stage is in the Universe's evaluation which occurs between 10-⁶ and after that Big Bang, is known as " BARYOGENESIS". In this point in time proton would be converted into neutrons and positrons by bombardment with antineutrons and neutrons would be converted back into electrons and protons by the interaction with a neutrino. The gamma Ray would be also spontaneously split apart to form both a electron and positron in a process known as pair production.
₁¹H +v→ ₀¹ + ₁⁰e ...........(1)
₀¹n + v→₁¹H + _₁⁰e ......... (2)
γ→₁⁰e + _₁⁰e ..... (3)
The first after few moments the Big Bang, is energy density was sufficiently equation (1) and (2) occurs roughly when the same rate, so that the numbers neutrons and protons were initially equal.
Although as the universe cooled as a expansion, the rate of proton formation to dominate, this occurred because the reaction given the equation (1) due to largely mass of the neutron. And it's result by the time that neutrino and anti- neutrino stopped interacting with the other elementary particles.
The composition of the universe considered of about 13% neutrons and 87% protons.
The first energy density of the universe was still sufficient strongly that the neutron and proton collisions would immediately break apart again. The next phase is the universe evolution know as Big Bang " nucleosynthesis" after the universe had cooled and further to a temperature around 10⁹ kelvin. And roughly three minutes after the initial expansion that density of the universe approximately 0.1gram/ cm³. The reaction of nucleosynthesis phase, the first nucleons was combined together to form heaviest nuclei. Before this point in the time to next largest nucleus (²H) were unable to form because, it's very low nuclear binding energies, which occurred in the series of fusion reaction below. The responsibility for the creation of most of the Helium and Hydrogen in the universe.
₁¹ H+ ₀¹n→ ₁²H + γ ..........(4)
₁²H + ₁²H →₂³He +¹₀n ........(5)
₁²H +₁²H → ₁³H + ₁¹ H.........(6)
³₂He + ₀¹n → ⁴₂ He + γ.........(7)
There were initially very less neutrons tha protons, the forming bond act as a limiting reagent, because that by the time is concluded, the universe considered of about Hydrogen 74%, Helium 25% and 1% Deuterium by mass.
The trace amount of Beryllium and Lithium were both also produced by the reaction below equation (8) and (9) The total synthesis of heavier mass elements was significantly reduced by the stability of the double magic number ⁴He nucleus. The continued nucleosynthesis from about 3 to 20 minutes followed by Big Bang. The BBN also helped prevent the formation of the heaviest mass elements. As a result, there's no nuclei heavily than ⁸Be was formed by the BBN.
₂³ He+ ⁴₂He →₄⁷Be....(8)
₁³H + ₂⁴He → ₃⁷ Li......(9)
The BBN was actually following by a cooling phase, which is allowed the neutrons to decay in to the proton particles. The temperature of the universe is in this point in time was no longer high enough for the fusion reactions to occurred and it largely consisted of matter. The theory is saying approximately 379,000 years after the Big Bang of the universe had little by little gradually cooled to a temperature of about 3000 kelvin. The is a finally cool to enough for electrons to cling to the nuclides to form from the first neutral atom. This is sometimes known as the chemistry phase in the evolution of the universe and began to organisms.
This theory was assumed approximately 10⁹ years after the big bang is had the temperature of the universe and cooled further about 20 kelvin temperature. The clouds of the interstellar matters began to coalesce under the influence of gravitation. The gradually density of these clouds increased until the protostars began to form.
Approximately 90 percentage of the stars in the universe at this point in time was stars having their size and composition similar to sun. The stars that are classified as main sequence stars, in the kinds of stars first type to form follows the Big Bang. The earliest stars referred to first generation- stars. The gravitational forces began contract matter together in the first stars, the increasing temperature and ionized the hydrogen and helium nuclei. The presence of neutrinos was no longer observed as they were during the BBN. When the pressure inside the stars the large interior temperature became a hot enough for nuclear fusion to occur. The density is normally increased to ~100g/cm³ and internal temperature of stars reached minimum 4× 10⁶ kelvin, the gases were ignited and stellar nucleosynthesis was initiated. A minimum temperature greater than 10⁷ kelvin. Helium - 4 can be produced by the process known hydrogen burning, given by equation (8) and (9). This process is known as proton - proton chain it's depicted. The 1st step in this process the formation of D is rate-limting because it produces a anti-lepton and lepton and it's governed by the weather force. As a result the main sequence stars can burn for many billion of years.
¹₁H + ¹₁H →₁²H + −₁⁰e + γ......(10)
Proton - Proton chain in stellar nucleosynthesis
₁²H + ¹₁H → ³₂ He+ γ.......(11)
³₂He + ³₂He → ⁴₂He + ¹₁H + ¹₁H.....(12)
A star of the size of sun will continue to burns hydrogen atom until the most of it's core is consumed. As the stars contracts, if it's mass is greater than 10³⁰ kilogram, and more density helium atom that accumulated in the core of the stars increase it's internal temperature to the point where helium burning can occurs. This heating of the core to temperature is greater than 2× 10 ⁷ kelvin and a density of 105gram/ cm³ causes an expansion of the star's in outer surface and creating a biggest RED Giant star.
Below the equation (13) and (14) two ⁴He nuclei and it's fuse together to form ⁸Be which turning can fuse with another ⁴He nuclei to make the a ¹²C nuclide. Because these total net reaction involves the fusion of 3 alpha particles, the first two steps in the mechanism are called triple alpha process.
But this three types of body process, the reaction is very slow, allowing Red Giant stars to continue to burn for 10⁷ to 10⁸ years. The sun will become a Red Ɡiant ,the swelling in size to engulf all of the inner planets.
₂⁴ He+ ₂⁴He → ₄⁸Be +γ..........(13)
₄⁸Be + ₂⁴He → ₆¹²C + γ..........(14)
The ⁸Be nucleus normally formed by equation (13) and it's metastable ion, which has half life of about 10-⁶ seconds. Unlikely this reaction given equation (14) can be occur with the probability. However, the energy of the ⁸Be ground state has exactly almost the same exact value as the energy of two α- particles and the reaction given by equation (14) generates about the equal amount of energy as an excited state of ¹²C. It's not coincidence of this resonant process, probably wouldn't be enough ¹²C in the universe to support the existence of carbon-based life forms.
The reaction of ⁴He with ¹²C to generating ¹⁶O below the equation (15) it's a very slower process. However once it's occurred, in both this reaction and given by equation (16) to form ²⁰Ne are exothermic, which is account for the cosmic abundance of the below two chemical elements.
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