Periodic Table
Find all 118 elements and explore atomic weights, isotope mass numbers and approximate element properties.
About this tool
Find an element by exact symbol or atomic number, or by part of its English or translated name. Category and search work together. Matching elements keep their positions; the others are dimmed. Clear filters restores all 118 elements. Groups are numbered across the top, periods down the left. The two detached rows belong to periods 6 and 7; they do not assign all their members to group 3.
Click an element to open its properties. Tab enters the matching buttons; left/right follow atomic number, up/down move between rows, Home/End reach the first/last match. Enter or Space opens details. Close returns focus to the element. Search, category and selection survive navigation and reload.
Values are approximate legacy reference data, not a certified current database; measurement conditions and predictions are not consistently specified. Standard atomic weights are dimensionless. Bracketed A identifies a selected isotope mass number, not necessarily the longest-lived isotope. Missing values and half-lives remain unknown; abundance does not prove stability. Helium has no ordinary melting point at ambient pressure; carbon and arsenic have a sublimation value instead of ordinary melting/boiling values.