Page 227 - A Life - my Live - my path

Appendix

Appendix 1 : Fusion and fission

It's all about temperature and pressure.

In practice, the periodic table lists the 92 stable elements
174
nd
found in nature. The 92 is uranium. Elements after the
92nd are called trans uranium .
175
Another table lists the 1,525 known isotopes, with 325
naturally occurring and 1,200 artificially produced in
nuclear reactors. They have no stable isotope.

The Big Bang 176
Immediately after the Big Bang, there was energy, lots of
energy, and all the elementary particles were independent of
each other. This state of matter is called "plasma". Next
came gases, liquids and solids.
The high temperatures (which can reach billions of degrees) and
pressures allowed a few particles to "fuse" to create other
particles. Gradually, the first nuclei appeared, as did the first
atoms.

174 MENDELEIEV table. The elements are classified by the number of protons.
The 1st is hydrogen, the last is uranium.
175 These are all radioelements with no stable isotope.
They are produced artificially, in nuclear reactors in the case of the lighter
elements, and by particle accelerators in certain research laboratories in the
case of the heavier elements.
176 The Big Bang is the most widely accepted scientific theory to explain the birth
of the Universe.
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