Final answer:
Knowing the number of valence electrons in an element helps to identify it by comparing it to the periodic table.
Step-by-step explanation:
The number of valence electrons in an element helps to identify it because the properties and reactivity of elements are determined by their valence electrons. Valence electrons are the outermost electrons in an atom and they are responsible for forming chemical bonds and determining the element's behavior. By knowing the number of valence electrons in an unknown element, we can compare it to the periodic table to find a matching element with similar properties.
Learn more about Linking atomic structure to the periodic table