Periodic Table of Elements

At a glance

This interactive periodic table shows all 118 known chemical elements in their familiar grid layout. You can search by name, symbol, or atomic number, highlight one family of elements at a time using the colored legend, and click any element to open a detail panel with its atomic mass, state at 20°C, melting and boiling points, density, electron configuration, electron shells, period and group, and the person or team credited with its discovery. It is useful for students checking homework, teachers preparing a lesson, and anyone who just wants a quick, reliable lookup.

• All 118 elements, placed in a 18-column grid with lanthanides and actinides in two rows below
• Search that dims every element that does not match what you type
• Nine color-coded categories that you can click to isolate
• A detail panel for each element, plus direct links such as ?element=26 for iron

How the tool works

The element data is stored in the page and comes from the open-source Periodic-Table-JSON dataset. Each element has a position (column and row) so the grid is drawn exactly where the element belongs. When you click a cell, a small script reads that element's record and fills in the panel. Searching compares what you type against the element's name, symbol, and atomic number, and every non-matching cell is dimmed. Clicking a legend item dims everything outside that category. All of this runs in your browser; nothing you type is sent anywhere. Empty fields, such as the melting point of a few of the heaviest elements, are left out of the panel instead of being filled with a guess.

How is the periodic table organized?

The periodic table arranges elements in order of atomic number (the number of protons in the nucleus). Rows (periods) represent the number of electron shells, and columns (groups) group together elements with similar chemical properties. Elements in the same column tend to have the same number of electrons in their outermost shell, which is why they behave similarly. Groups are numbered 1 to 18 under the current IUPAC convention, and there are seven periods. Period 7 is now complete with element 118.

The two rows placed below the main grid are the lanthanides (elements 57 to 71) and the actinides (elements 89 to 103). They belong inside the table, between the s-block and d-block, but if they were drawn there the table would be 32 columns wide, so they are conventionally pulled out and shown underneath to keep the layout compact. In this tool the detail panel lists those elements under group 3, following the dataset.

Understanding the element categories

• Alkali metals: Highly reactive metals that react vigorously with water (lithium, sodium, potassium, etc.).
• Alkaline earth metals: Slightly less reactive than alkali metals, but still quite reactive (magnesium, calcium, etc.).
• Transition metals: The largest group, filling the middle of the table — includes familiar metals like iron, copper, gold, and silver.
• Post-transition metals: Softer, lower-melting metals than the transition metals (aluminium, tin, lead, etc.).
• Metalloids: Elements with properties between metals and nonmetals (silicon, germanium, etc. — widely used as semiconductor materials).
• Nonmetals: Elements that lack a metal's characteristic luster or electrical conductivity (carbon, oxygen, chlorine, etc.).
• Noble gases: Stable gases that rarely react with other elements (helium, neon, argon, etc.).
• Lanthanides & actinides: Placed in a separate block below the main table — widely used in magnets, batteries, and nuclear applications.

Category boundaries are conventions, and sources draw them slightly differently. For example, hydrogen sits in group 1 of the grid but is classed as a nonmetal here, and some textbooks place the boundary of metalloids differently. When a category is only a theoretical prediction for a very heavy element, the panel shows a note saying so.

How to use it, with an example

1. Search or click. Type "Fe", "iron", or "26" to dim everything except iron, then click it.
2. Read the panel. You will see the symbol in the category color, the name, the atomic number, and the property chips.
3. Compare neighbors. Click down a column, for example lithium, sodium, and potassium, and notice how melting points fall as you go down.
4. Filter by family. Click "Noble gas" in the legend to see where those seven elements sit on the right edge.

Example of reading a result: choose oxygen (atomic number 8). Its period is 2, so it has two electron shells, and its group is 16, so it has six electrons in its outer shell. Its panel lists its state at 20°C as a gas, which you can compare with bromine and mercury, the only two elements that are liquid near room temperature, if you click on them.

A short history

In 1869 the Russian chemist Dmitri Mendeleev published a table that arranged the known elements by atomic weight and left gaps for elements that had not yet been found. Elements discovered later, such as gallium, scandium, and germanium, fit those gaps, which helped convince chemists that the pattern was real. In 1913 Henry Moseley showed that atomic number, rather than atomic weight, is the correct ordering principle, and that is the arrangement used today.

The newest additions are elements 113, 115, 117, and 118. After their synthesis was confirmed, IUPAC approved their names in November 2016: nihonium (Nh, element 113, named for Japan), moscovium (Mc, 115, for the Moscow region), tennessine (Ts, 117, for Tennessee), and oganesson (Og, 118, for the nuclear physicist Yuri Oganessian). Their addition completed the seventh period.

Accuracy, limits, and privacy

Values shown are standard reference data, rounded for display. The atomic mass of an element is an average over its naturally occurring isotopes, so it is not a whole number for most elements. For elements that have no stable isotopes, the figure typically reflects a specific isotope. Melting points, boiling points, and densities are measured under standard conditions and can differ between sources by small amounts. For the heaviest synthetic elements, only a few atoms have ever been made, so some properties are predicted by theory rather than measured. This is flagged in the panel. For lab work, regulatory use, or publication, check an authoritative source such as IUPAC or a current handbook rather than relying on this page alone. The tool stores nothing about you.

Common mistakes and myths

• Confusing atomic number with atomic mass. The atomic number is the proton count and defines the element; the mass is a weighted average of the isotopes.
• Assuming all metals are solid. Mercury is a liquid at room temperature, and gallium melts at a temperature only slightly above it.
• Thinking symbols always match English names. Na (sodium), K (potassium), Fe (iron), and Au (gold) come from Latin names.
• Thinking the table is finished forever. Researchers continue to attempt synthesis of elements beyond 118, though none has been confirmed.
• Reading the lanthanide row as a mistake. It is a layout choice to save width, not a separate table.

Frequently Asked Questions