This page explores individuality through identifiers such as cell phone numbers and DNA, then shifts to atomic theory, explaining how atomic numbers define elements based on proton counts. It emphasiz...This page explores individuality through identifiers such as cell phone numbers and DNA, then shifts to atomic theory, explaining how atomic numbers define elements based on proton counts. It emphasizes the organization of the periodic table for predicting element properties and notes that atoms are neutral, with equal numbers of protons and electrons, underscoring the foundational aspect of atomic structure.