CHEM 107 Lecture Notes - Lecture 47: Isoelectronicity, Periodic Trends, Atomic Number
Document Summary
Noble gases have chemically-stable outer-shell electron configurations (ns2np6) Tend to lose electrons to form ions that are isoelectronic with noble gases. Tend to gain electrons to form ions that are isoelectronic with noble gases. The energy required for the complete removal of 1 mol of electrons from 1 mol of gaseous atoms or ions (units are generally kj/mol). The energy required to take one electron away. Low ionization energy easier to remove electrons. Atoms with a low ie tend to form cations. High ionization energy harder to remove electrons. Atoms with a high ie tend to form anions (except the noble gases) Notice that periodic trends for ie are the opposite of those for atomic size. Give the total number of protons and electrons in each ion. Specify the number of valence electrons for each atom. O = 6 (it is in group 6a) Just like with e- configuration, add single e-s to each side and then start paring.
