Transcript Where do elements come from? - Londonderry NH School District

Where do elements
come from?
Remember the Big Bang?
The theory states that
Universe today retains an
imprint of its initial cosmic
mixture of elements
The Universe consists mostly of …
Hydrogen H (75%)
and Helium He (24%)
Plus some Lithium, Beryllium and
Deuterium (1%)
The First Elements in the Early
Universe
Hydrogen and Helium
were the first elements
We viewed many other
element’s wavelengths
using spectroscopy.
Where do the other 90
natural occurring elements
originate or come from?
Elements in the stars
as viewed from Earth
Elements are made in stars
• Stars are hot ionized balls
of gas (plasma) full of
energy that is held
together by gravity
• Everything is made from
the elements created in
massive stars. Stars are
huge factories producing
the elements found in the
Universe.
Nuclear Fusion
Combining of two atomic nuclei
• The star creates heat and light by nuclear fusion.
Light Hydrogen atoms fuse into Helium atoms.
http://www.atomicarchive.com/Movies/Movie5.shtml Click to View Video
http://www.astro.ubc.ca/~scharein/a311/Sim.html Fusion Simulation
Lighter Elements, atomic # <27
• Lighter elements fuse to create heavier
elements like carbon and oxygen; During
the life span of a star fusion can take place
up to the formation of Iron
Heavier Elements, atomic # >26
• Supernovas, with their extreme heat and
pressure, create all the elements heavier
than Iron (Fe)
• After a supernova, a nebula is formed which
contains heavier elements
• This nebula forms new stars with a higher
concentration of heavier elements
• These stars may also form a supernova, forming
a nebula with even a higher concentration of
heavier elements
• Leading eventually to the correct combination of
different elements necessary to form life