The periodic table of elements with the symbol 'Na' for Sodium highlighted in a red box. The atomic number 11 and atomic mass 22.9897 are displayed below the symbol. The element is shown in a larger size with a red and brown color scheme, and the surrounding elements are in their normal size and color. The periodic table is labeled 'How the Periodic Table Identifies Atoms' with the phrase 'Atomic Mass: Average Atomic Mass' above it. The text 'Related to Number of Protons and Neutrons' is placed below the table.