But poor old sodium (core charge 1+, large radius) can only have the weakest of attraction for chlorine's unpaired electron. The chlorine atom (core charge 7+, small radius) would strongly attract sodium's single valence electron into its one valence vacancy.
Suppose that sodium and chlorine were to form a covalent bond, as we described in Lesson 5. If you compare any two metal and non-metal atoms (except H) you will find the same pattern.ģ. Sodium's electron would be much more strongly attracted to chlorine's valence shell, where it would be much closer to a much greater core charge. It is only weakly attracted to its small distant atomic core. In other words: if an elements looks like a metal, it is also likely to readily lose valence electrons.Ĭonsider sodium's single valence electron. This explains virtually all of the common properties of the non-metals. In fact, only these 12 or so elements are able to grab and hold other atoms' electrons. Non-metals have large core charges and small radii, therefore they have strongly held valence electrons. Metals have small core charges and large radii, therefore they have loosely held valence electrons. The noble gases are colored brown, to indicate that they are inert.Īll of the properties of metals (lustre, thermal and electrical conductivity, malleability, chemical activity) can be easily explained by the Ross model. Non-metals are given the warm colors yellow, orange, and red to indicate electronegativity greater than 2. The metals are given cool colors, blue to purple, to indicate electronegativity less than 2. Note that hydrogen has the same colour / electronegativity as the metalloids.
All of them have electronegativities close to 2. On the Ross Table, the metalloids are colored green. Metals and Non-metalsīoron, silicon, and arsenic lie along the dividing line between the roughly 72 naturally occurring metals and 12 or so naturally occurring non-metals. The whole process is driven by energetics, not by atoms "wanting" anything. We can do better than all of that. First, we must admit that ionic bonding is a more complex process than covalent bonding. Memorize math that looks like lowest common denominator.Memorize list of "ionic valencies ," some of which violate (4).Na and F do opposite things to get the holy grail: the "full octet.".
Believe that fluorine "wants" this, sodium "wants" that.6 - Ionic Bonding Since the ChemStudy curriculum was released in 1963, ionic bonding was always first.