Periodic Table of Elements

How to use

1. Search any element — type an element name, symbol, or atomic number into the instant search bar.
2. Filter by chemical family — isolate alkali metals, transition metals, nonmetals, halogens, or noble gases.
3. Understand periods and groups — navigate 7 horizontal periods and 18 vertical IUPAC groups.
4. Inspect atomic properties — review relative atomic mass, electronegativity, oxidation states, and melting/boiling points.
5. Solve chemistry problems — an interactive reference tool for stoichiometry, electron orbitals, and compound calculations.

What is the Periodic Table of Elements?

The periodic table arranges chemical elements in order of increasing atomic number, which reflects the number of protons in an atomic nucleus.

Formulated by Dmitri Mendeleev in 1869, the periodic law enabled scientists not only to classify existing elements but also to accurately forecast the properties of undiscovered ones.

Today's table contains 118 officially recognized chemical elements, ranging from Hydrogen (H, 1) to Oganesson (Og, 118).

Periods and Groups Explained

The table's grid structure reveals profound atomic relationships:

• Periods (7 horizontal rows) — the period number corresponds to the number of electron shells occupied in an atom.
• Groups (18 vertical columns) — elements in the same column share identical valence electron configurations and exhibit similar chemical reactivity.

Major Element Categories

• Metals — make up over 80% of elements; malleable, ductile, lustrous, and good conductors of heat and electricity (Fe, Cu, Al, Au).
• Nonmetals — essential for organic life; gases, liquids, and solids with high electronegativity (O, N, C, S, Cl).
• Metalloids — intermediate semiconductor elements (B, Si, Ge, As) forming the backbone of modern microelectronics.
• Noble Gases — Group 18 inert gases (He, Ne, Ar, Kr, Xe, Rn, Og) with closed valence shells and minimal reactivity.
• Alkali & Alkaline Earth Metals — highly reactive metals of Groups 1 and 2 readily forming basic ionic salts.

Trends You Can Read Directly From the Table

• Proton and electron counts directly from the atomic number.
• Electron shell count directly from the period row.
• Valence electrons and typical oxidation states from group columns.
• Periodic trends: atomic radius shrinks left-to-right; electronegativity rises toward Fluorine.

Applications of the Periodic Table

• Education — learning chemical reactions, balancing equations, and calculating molar mass.
• University Research — quantum chemistry, thermodynamics, and molecular engineering.
• Laboratories — reference guide for spectroscopy, synthesis, and materials analysis.
• Industry — designing batteries, alloys, pharmaceuticals, and catalysts.

How to Study the Table Effectively

• Master the first 20 elements from Hydrogen (1) to Calcium (20) first.
• Learn key families together: alkali metals, halogens, noble gases.
• Practice with interactive tools during real problem solving rather than rote memorization.