The Periodic Table of Elements

In 1869, Dmitri Mendeleev arranged 63 known elements by atomic weight and noticed a repeating pattern of properties. He left gaps for elements he predicted would be discovered, specifying their properties with remarkable accuracy. Gallium, germanium, and scandium filled three of those gaps within 15 years. Today the table holds 118 confirmed elements, from hydrogen (atomic number 1, the lightest) to oganesson (118, synthesized in 2002). Every pick on this page draws uniformly from this complete set.

Categories of Matter

Elements fall into categories based on their physical and chemical properties. Alkali metals (lithium, sodium, potassium) react violently with water. Noble gases (helium, neon, argon) resist bonding entirely. Transition metals (iron, copper, gold) fill the wide center of the table and account for most metallic elements. Lanthanides and actinides extend the table into two separate rows of 14 elements each. The Categories counter in the statistics panel tracks how many of these distinct groupings you encounter.

States of Matter

At room temperature (25°C), most elements are solid. Just two are liquid: mercury (the only liquid metal) and bromine (a dark red fuming halogen). Eleven elements exist as gases, including the entire noble gas column and atmospheric staples like nitrogen and oxygen. The superheavy elements beyond lawrencium (104-118) have been synthesized in quantities too small to determine their bulk physical state. The States counter reveals this asymmetry as you explore.

In the Classroom

Element discovery turns the periodic table from a reference poster into an active exploration. Have students press Space and locate each element on the table below, observing how the table fills. Which regions fill first? Transition metals (38 elements) dominate statistically. Challenge the class to discover all noble gases (6 elements) or all alkali metals (6 elements). The probability of completing a specific category provides a concrete exercise in geometric distribution.

Private by Architecture

The element database (118 entries) ships with this page. Your device selects each element using crypto.getRandomValues(). No data leaves your browser. Share the URL and your friend discovers their own independent element from their own device.