CHEM H90 Lecture Notes - Lecture 5: Plutonium, Beryllium
Lecture #5
• origins of elements
o energy from the sun results from a hydrogen nuclear fusion reaction
o first elements are H & He and most abundant
• beyond helium
o stellar nucleosynthesis leads to stars with heavy cores
o as star gets old, uses up its H and He
o produce heavier elements only up to Fe
• heavier elements: beyond Fe
o V, CA, Pu, Ag, Sn, U, Cs, Hg, Au, I, Pt, Zn,. etc.
• element abundance in universe
o H & He most common
o Beryllium least common
• element abundance on earth
o rock-forming elements
▪ Oxygen, Silicon, etc.
o rarest metals
▪ Au, Pt, Ir, etc.
• in human body
o O, C, H, N, Ca, P, K, S, Na, Cl, Mg
o main elements that compose the human body are shown from most abundant (by
mass) to least abundant
• exotic elements
o elements with atomic numbers higher than 92 (uranium) typically don’t exist on
Earth and have to be made by nuclear synthesis
o the first synthesized elements were named after the planets
▪ Ur – uranium
▪ Np – neptunium
▪ Pu – plutonium
• what we should have learned
o how to do better on HW
o about 100 elements, each with its own name
o where atoms in you and your planet came from
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