This happens because the number of filled principal energy levels (which shield the outermost electrons from attraction to the nucleus) increases downward within each group. Second, moving down a column in the periodic table, the outermost electrons become less tightly bound to the nucleus. As this happens, the electrons of the outermost shell experience increasingly strong nuclear attraction, so the electrons become closer to the nucleus and more tightly bound to it. First, electrons are added one at a time moving from left to right across a period. In addition to this activity, there are two other important trends. Stable octets are seen in the inert gases, or noble gases, of Group VIII of the periodic table. Elements tend to gain or lose valence electrons to achieve stable octet formation. Using the variable n to represent the number of the valence electron shell, write the valence shell electron configuration for each group. Vocabulary electronegativity Introduction Around 1935, the American chemist Linus Pauling developed a scale to describe the attraction an element has for electrons in a chemical bond. use the general trends to predict the relative electronegativities of atoms. These trends can be predicted merely by examing the periodic table and can be explained and understood by analyzing the electron configurations of the elements. The shape of the periodic table reflects the order in which electron shells and subshells fill with electrons. describe the trends that exist in the periodic table for electronegativity.

The periodic table arranges the elements by periodic properties, which are recurring trends in physical and chemical characteristics.

Periodic table trends valence electrons