History of the Universe eBook. 398 pages, 300 illustrations only £5.99
Dust and PlanetsWe can now watch how atoms begin to interact with each other. Things are going to be a lot more interesting from now on, as gradually larger and more complex assemblies of atoms joined together, ultimately creating you and me! But the story starts in a fairly simple way. We have seen that a nova or supernova are major ways in which the new, heavy nuclei made in red giant stars are sent out into the galaxy, ready to be incorporated into new stars and planets. If this re-cycling did not happen, planets and life could never have begun. IonsAs they shot out of the star, some nuclei gained too many electrons (giving them a negative electric charge) while others had too few (giving them a positive charge). This type of atom is called an ion. An ion is an atom which has lost or gained an electron. Such an atom carries an electric charge, so it will strongly attract or repel other ions. Ionic BondIf a negative ion meets a positive one, their opposite charges attract strongly and glue the atoms together. This type of gluing is called an ionic bond. Ionic bonds were first formed as atoms emerged from a supernova. They are important today in holding the atoms together in many rocks on the Earth, as well as materials like table salt. When a lot of positive and negative ions meet they can form a solid with a regular arrangement of atoms, called a crystal, as shown in the next diagram. Ionic bonds hold atoms strongly together Because the ionic bond is strong, many crystals were able to form and survive even in the hot gas surrounding an exploding star.
History of the Universe eBook. 398 pages, 300 illustrations only £5.99 |
eBook only £5.99 398 pages, 300 images "I find the science fabulous...an extremely useful teaching tool." Professor David Christian. Follow @WykenSeagrave |