Periodic table guides
The ideas you need to read and use the periodic table, one topic at a time.
How to Read the Periodic Table: From a Single Cell to the Block Structure
A beginner's guide to the periodic table: atomic number, symbol and atomic weight, groups and periods, s/p/d/f blocks, and the metal–nonmetal border.
02History of the Periodic Table: From Triads to a Complete Seventh Period
From Döbereiner's triads and Newlands' octaves to Mendeleev's 1869 predictions, Moseley's atomic numbers, Seaborg's actinides and the 2016 completion of period 7.
03Alkali Metals and Alkaline Earth Metals: A Guide to Groups 1 and 2
Groups 1 and 2 explained: properties of alkali and alkaline earth metals, reactivity trends, flame test colors, everyday uses and where hydrogen belongs.
04Transition Metals: How d Orbitals Create Color and Catalysis
Why transition metals show many oxidation states, form colored complexes and make great catalysts, explained through d orbitals, with iron, copper and more.
05The p-Block: Metalloids, Halogens and Noble Gases
A tour of groups 13–18: from metals to nonmetals, metalloids in semiconductors, reactive halogens, and the noble gases that turned out to form xenon compounds.
06Lanthanides and Actinides: A Guide to the f-Block
The f-block explained: the lanthanide contraction, why rare earths are not really rare, transuranium elements and how radioactive actinides are used.
07Periodic Trends: Atomic Radius, Ionization Energy, Electronegativity and Electron Affinity
How atomic radius, ionization energy, electronegativity and electron affinity change, why effective nuclear charge drives them, and exceptions like N/O and F/Cl.
08Electron Configuration Explained: Aufbau Principle, Pauli Exclusion and Hund's Rule
Write electron configurations with the Aufbau principle, Pauli exclusion and Hund's rule: orbital boxes, noble gas shorthand and the Cr and Cu exceptions.
09How to Calculate Molar Mass: From Chemical Formula to g/mol and Mass Percent
Calculate molar mass step by step: the mole, counting atoms, parentheses, hydrates like CuSO₄·5H₂O and mass percent, with CIAAW 2024 worked examples.