There are 118 elements on the periodic table. Elements are identified by their atomic number, which equals the number of protons. Elements are arranged in order of increasing atomic number
Electronegativity is not uniquely defined and may vary by definition. Values are taken from WebElements as consistent set. Some highly radioactive elements have predictions not marked. Francium's value (0.7) predates relativistic calculations
IUPAC has officially identified and named 118 chemical elements. Elements are defined by specific number of protons in atomic nucleus. Periodic table visualizes all 118 elements by chemical properties. Elements can be organized by proton number or other properties. List format can be linear or arranged by chemical symbols
Periodic table arranges elements by atomic number in rows and columns. Elements in same group show similar chemical characteristics. Table divided into four blocks: s, p, d, and f-block. Elements are arranged by increasing atomic number
Electron configuration shows the arrangement of electrons in atomic orbitals. Electrons orbit around nucleus in different-shaped regions called shells. Each shell contains electrons with same energy level
Molecular weight is the total mass of all atoms in a molecule. It is measured in Atomic Mass Units (amu)