Formation-of-Light-and-Heavy-Elements.pdf

FORMATION OF LIGHT ELEMENTS AND HEAVY ELEMENTS NUCLEOSYNTHESIS NUCLEO SYNTHESIS Nucleus Creating something new by combining separate materials Nucleosynthesis is the process by which elements are formed through nuclear reactions. Nucleus 1...

FORMATION OF LIGHT ELEMENTS AND HEAVY ELEMENTS NUCLEOSYNTHESIS NUCLEO SYNTHESIS Nucleus Creating something new by combining separate materials Nucleosynthesis is the process by which elements are formed through nuclear reactions. Nucleus 1 Nucleus 2 Nucleus 1 Nucleus 2 New Nucleus  NUCLEOSYNTHESIS TIMELINE 1. BIGBANG NUCLEOSYNTHESIS 2. STELLAR NUCLEOSYNTHESIS I. PROTON-PROTON CHAIN REACTION II. CARBON-NITROGEN-OXYGEN (CNO) CYCLE III. TRIPLE ALPHA PROCESS IV. ALPHA LADDER PROCESS 3. NEUTRON CAPTURE I. R PROCESS (RAPID NEUTRON CAPTURE PROCESS) II. S PROCESS (SLOW NEUTRON CAPTURE PROCESS) What is Big Bang Nucleosynthesis?  0 to 3 minutes after the Big Bang the universe was extremely hot and dense As it expanded and BIG BANG cooled, protons and neutrons combined NUCLEOSYNTHESIS to form light nuclei.  As it expanded and cooled, protons and neutrons combined to form light nuclei. n p n p p p p p n n n p n n p Deuteron Triton p p n n n  Deuteron Triton Isotope of Hydrogen (H) Isotope of Hydrogen (H) Consist of two (2) Consist of three (3) subatomic particles: subatomic particles: 1 proton and 1 neutron 1 proton and 2 neutrons  HELIUM-4 p p n n p p n n Deuteron + Deuteron Triton + Proton  LITHIUM-7 p p n n p n n HELIUM-4 + TRITON  BERYLLIUM-8 p p n n p p n n HELIUM-4 + HELIUM-4  During the big bang nucleosynthesis, the first four light elements are formed. Hydrogen Helium Lithium Beryllium  What is Stellar Nucleosynthesis?  Few billion years after the Big Bang, the universe continue to evolve. STELLAR Stellar nebula began to NEBULA form Stellar nebula are clouds of gas and dust in space where new stars are born.  After the stars are born from the stellar nebula it begins to evolve. STELLAR NUCLEOSYNTHESIS Within stars, nuclear fusion reactions combine lighter elements into heavier ones. STELLAR NUCLEOSYNTHESIS  NUCLEAR FUSION REACTIONS (STELLAR NUCLEOSYNTHESIS) I. PROTON-PROTON CHAIN REACTION II. CARBON-NITROGEN-OXYGEN (CNO) CYCLE III. TRIPLE ALPHA PROCESS IV. ALPHA LADDER PROCESS  MEDIUM SIZE STARS Positron Positron PROTON-PROTON CHAIN REACTION  CNO Cycle Stands for Carbon-Nitrogen-Oxygen Cycle Infusing Hydrogen to form Helium Process more dominant in high mass stars.  HIGH MASS STARS Atomic Number Carbon-6 Nitrogen-7 Oxygen-8 CNO Cycle  ALPHA 2 protons and 2 neutrons PARTICLE NO electrons  ALPHA PARTICLE Helium-4  Uses three alpha partices Three (3) Helium Nuclei TRIPLE combine to form Carbon Process more dominant in ALPHA PROCESS high mass stars.  HIGH MASS STARS Atomic Number Helium-2 Beryllium-4 Carbon-6 Triple Alpha Process HIGH MASS STARS 2. Alpha Ladder Process  This process is used where heavier elements than Iron Neutron (Fe) are formed. Capture REPELS Neutron capture bombardment will enter  R PROCESS (RAPID NEUTRON CAPTURE PROCESS) S PROCESS (SLOW NEUTRON CAPTURE PROCESS)  R-Process S-Process Neutrons bombardments is slow (it Neutrons bombardments is fast takes thousand years) (usually takes 1-2 seconds) Happens in dying stars Happens during supernovae where a lot of energy is formed During alpha process it produces a lot of pre-neutrons which causes to have slow bombardments of Captured neutrons turns to neutrons protons which changes the identity of an element. Captured neutrons turns to protons which changes the identity of an element.  STELLAR EVOLUTION  PROTON-PROTON Carbon-Nitrogen- TRIPLE ALPHA PROCESS & CHAIN REACTION Oxygen (CNO) CYCLE ALPHA LADDER SLOW NEUTRON CAPTURE PROCESS (S-PROCESS) BIG BANG NUCLEOSYNTHESIS RAPID NEUTRON CAPTURE PROCESS (R-PROCESS) Carbon-Nitrogen- TRIPLE ALPHA PROCESS & Oxygen (CNO) CYCLE ALPHA LADDER