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2.4 The Discovery of the Electron -- Part 3
Elements Ions can also be negatively charged.
For example, neutral fluorine atoms have nine protons and nine electrons, but in many chemical reactions they gain one electron to form F- ion.
A charge of 1- is created when the F- ion contains 9 protons and 10 electrons.
The neutral atom is less common than the ion for many elements.
Most of the time, lithium and fluorine occur as ion.
Ions behave differently than their atoms.
sodium atoms are very unstable and react violently with most things.
The time in table salt is a useful mnemonic device.
There are many different kinds of Ele ments on the planet.
The story of element formation is as old as the universe itself, and we have to go back to the beginning to tell it.
The Big Bang theory states that the universe began as a hot, dense collection of matter and energy that expanded rapidly.
Within a few minutes, the first atomic nuclei were formed: hydrogen and helium.
The two elements are the most abundant in the universe.
The stars and galaxies were the nurseries for all other elements.
We will discuss in more detail in Chapter 21 how stars are fueled by nuclear fusion.
Under the conditions within the core of a star, hydrogen nuclei can combine to form helium.
Stars emit a lot of heat and light because they give off enormous quantities of energy.
A star can be powered by the fusion of hydrogen and helium.
If a star is large enough, the helium that builds up in its core can be used to make carbon.
If the star is large enough, the carbon builds up in the core and can form heavier elements.
The nucleus of iron is very stable.
The light elements formed during the lifetime of the star through the fusion processes are able to capture extra neutrons within a supernova.
The formation of elements heavier than iron is a result of the transformation of the neutrons into protons.
The elements are present in Nebula as the supernova continues to expand.
This image was taken out into space, where it can be incorporated into the Hubble Space Telescope and show planets that are similar to our own sun.
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