Periodic Variation of IE and EA
Before we can broaden our discussion of ionic bonding beyond a treatment of lithium hydride, we need to know how ionization energyThe quantity of energy required to remove an electron from a neutral atom or molecule or from a positive ion. and electron affinityThe energy change that occurs as an atom or negative ion accepts an electron. The first electron affinity applies to a neutral atom combining with an electron; the second electron affinity applies to a minus-one ion accepting an electron; etc. Sometimes defined as negative when the negative ion is more stable than the neutral atom and sometimes defined as positive for the same circumstance; check the definition in any source of data. vary depending on an element’s position in the periodic tableA chart showing the symbols of the elements arranged in order by atomic number and having chemically related elements appearing in columns.. We will then have a much clearer idea of what elements are likely to form ionic compounds. At the same time we will find that these properties have some features which are interesting for other reasons.