CHEM 111 Lecture 5: CHEM111 Class 05
21 Dec 2015
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Document Summary
Chem111 lecture 5 locating and naming compounds. It is relative to one-twelfth the mass of an atom containing 6 protons and 6 neutrons and 6 electrons. There are isotopes, which are atoms with a different number of neutrons (add example problem for abundance) Recognized that observed properties of the elements recurred in a pattern when the elements were arranged in order of atomic weight. The name of an element often means relevant compounds of the element. Chemistry means chemical reactions, the rearrangement of atoms in the reactants to form products, the breaking and making of chemical bonds. Bonds are formed when atoms get close enough together and the electrons rearrange to create a region of negative charge that overcomes the mutual repulsion of the positive nuclei. So periodic properties in the chemistry of the elements are about periodic properties of their electrons. This means that electrons are not arranged in the same way in every atom.
