Alkali Metal: These are highly reactive metals found in Group 1 of the periodic table. Sodium is one of the alkali metals.
Atomic Mass: It refers to the mass of an atom relative to carbon-12 and is expressed in atomic mass units (amu). Sodium has an atomic mass of approximately 23 amu.
Electron Configuration: This term describes how electrons are arranged around an atom's nucleus. The electron configuration for sodium is 2-8-1, meaning it has two electrons in its innermost shell, eight electrons in its second shell, and one electron in its outermost shell.