Final answer:
c) Showing valence electrons
The primary purpose of a Lewis electron-dot symbol is to show valence electrons around an atomic symbol. It is a visual representation used to predict bond formations in chemical compounds. The correct answer is (c) Showing valence electrons.
Step-by-step explanation:
The primary purpose of a Lewis electron-dot symbol is to represent valence electrons of an atom. This diagrammatic approach helps in visualizing the valence electron configuration of an element and is particularly useful for understanding how atoms bond in molecules. The dots in a Lewis symbol surround the elemental symbol, with each dot indicating a single valence electron.
Option (c) Showing valence electrons is the correct answer to the question asked. Lewis electron dot diagrams do not represent atomic mass, illustrate general electron configurations, or depict isotopic abundance. Instead, they provide a simple, yet effective way to keep track of valence electrons as they participate in bond formation.
For example, the Lewis electron dot symbol for hydrogen is a single dot next to the H symbol, indicating one valence electron. The number of dots corresponds to the number of valence electrons and can vary depending on whether the species is a cation (fewer dots) or an anion (more dots).