Module 4

• Nucleosynthesis is the study of nuclear processes responsible for the formation of the elements
• Atomic number is the fingerprint of an atom; gives the elements' unique number of protons
• Mass number gives the total number of protons and neutrons
• Atom is the basic building block of chemistry; smallest unit of matter
• Isotopes are atoms with the same number of protons (or same atomic number) but different number of neutrons
• Nuclear fusion occurs when atomic nuclei combine to form a heavier element and sub atomic particles
• nuclear fusion- smaller nuclei collide to make larger nuclei, and energy is released in the form of electromagnetic radiation
• Big Bang Nucleosynthesis involves the production of all hydrogen, helium, and lithium; lights elements + beryllium
• Atomic orbitals- a 3-dimensional regions where electrons are most likely to be found in an atom
• Neutron- neutral particle in the atomic nucleus alongside protons
• Atomic nucleus- positively charged center of the atom containing protons and neutrons
• Proton- positively charged particle in the atomic nucleus
• Electron- negatively charged subatomic particle orbiting the nucleus
• Stellar nucleosynthesis- process by which elements are formed within stars
• Stellar nucleosynthesis- this is where elements heavier than beryllium are formed, the abundances of these elements change as the stars evolve
• nuclear fusion - provides the energy for the star to keep burning
• hydrogen - the main fuel of stellar nucleosynthesis
• Hydrogen burning - powers stars for 90%; fusion of 4 hydrogen nuclei to form helium nucleus
• Helium burning - responsible for the production of carbon and oxygen
• low to average mass stars results to white dwarf
• large mass star results to neutron star
• very large mass star results to black hole
• formation of elements heavier than iron were formed via neutron capture process (s-process and r-process)
• s-process - produces lighter elements up to lead and bismuth (slow)
• r-process - produces elements as heavy as uranium (rapid)
• Supernova nucleosynthesis - star explosion
• Equilibrium Process - silicon burning produced a nuclear statistical equilibrium