Some definitions: Quarks: Building blocks of protons and neutrons Atom: Neutral charged assemblage of protons, neutrons, electrons Electron: Negatively charged sub-atomic particles that orbits around the atomic nucleus Atomic Nucleus: Present in the center of an atom consisting of proton and neutrons Element: A type of matter characterized by the number of protons in the atomic nucleus Isotope: A specific form of an element with a precise number of neutrons. Stable Isotope: An isotope whose atomic nucleus is stable Unstable Isotope: An isotope with an unstable nucleus which will undergo the process of radiometric decay.

The Big Bang: The Synthesis of Building Blocks of the Universe Astrophysicists tell us: ~ 12 to 15(?) billion years ago all matter and energy existed as a single "spark" Expansion of everything is commonly referred to as The Big Bang In the beginning the universe had an infinite temperature - Since the Bang Bang the universe has EXPANDED AND COOLED Let us look at the earliest history of the universe

THE UNIVERSE’S HISTORY 1 2 3 4

1. AT 10-32 seconds after the Big Bang - Matter separates from energy - Matter consists of tiny sub-atomic particles known as quarks 2. AT 1 to 100 seconds after the Big Bang - Temperature cooled enough to allow quarks to begin to come together - Form more familiar particles - PROTON (HAS A +1 CHARGE) - NEUTRON (HAS 0 CHARGE) - Protons and neutrons themselves can come together to form the atomic nuclei of elements - At this time the universe consisted mainly of the following atomic nuclei of the following elements

Hydrogen (H) 75% Helium (He) 25% Everything Else <1%

3. AT 300,000 years after the Big Bang - Besides protons and neutrons what else is present in an atom? - Electrons (HAS A -1 CHARGE) - Remember that an atom has a nucleus that consists of protons and neutrons - and electrons that orbit around this nucleus in a shell Basically, at this time the universe had cooled enough to allow electrons to enter into orbit around the nucleus of an atom.

DIGRESSION: There are different isotopes of Hydrogen Protons Neutrons Stability 1H 1 0 Stable 2H 1 1 Stable 3H 1 2 Instable Note that hydrogen always has one proton but its different Isotopes have different numbers of neutrons.

However, today the universe consists of more elements than just H and He that form a gigantic gas ball! 4. AT 1,000,000,000 years after the Big Bang - Stars and galaxies begin to form Inside all stars nuclear processes fuse atomic nuclei together - This process is nuclear fusion - RESULT: Larger elements up to number 26 (iron) are formed inside these stars

Iron AND YES YOU NEED TO LEARN ALL THE OTHER ELEMENTS LISTED ABOVE

But, what about the larger elements beyond iron (number 26) - Naturally occurring elements go up to number 92 (Uranium) Need processes much more violent then the typical nuclear fusion that occurs within a star. Large stars (more massive than 3 times the sun) have a tendency of blowing up at the end of their lives! - Such an explosion is called a SUPERNOVA - Note that a single supernova can out shine the light output of all of these other stars put together! - All the larger elements beyond iron have been made during these cosmic explosions.

RINGS OF MATERIAL THROWN OUT BY A SUPERNOVA