Periodic Table

A periodic table of all 118 elements in the standard 18-column layout. Tap an element to see its atomic weight, electron configuration, group, period, block, density, melting and boiling points and electronegativity.

How to use

1. Tap an element; its details appear below. The left and right arrow keys move to the previous or next element.
2. Type a name, symbol or atomic number in "Find".
3. Under "Colour by", choose "Category", "State at room temperature" or "Block". Tap a legend item to highlight only that group.
4. On a phone, switch "View" to "List". In the "Table" view, "Print" prints the table.

How it works

• Atomic weights are the IUPAC CIAAW standard atomic weights (2024). Elements without one show the mass number of their most stable isotope.
• Other properties come from the PubChem periodic table data. Temperatures are shown in K and °C, and a dash marks a value with no reliable measurement.
• English names use the IUPAC spellings aluminium, caesium and sulfur, with the other common spellings (aluminum, cesium, sulphur) alongside.

Questions and answers

What are groups and periods in the periodic table?

Groups are the columns (1 to 18); elements in a group behave similarly. Periods are the rows (1 to 7); for most elements the period number is the number of the outermost shell holding electrons.

Is it aluminium or aluminum?

Both name element 13, Al. Aluminium is the IUPAC spelling used here; aluminum is shown next to it.

Why do some atomic weights have square brackets [ ]?

They are radioactive elements without a standard atomic weight, such as technetium (Tc) and plutonium (Pu). The mass number of the most stable isotope is shown instead.

Why are the lanthanoids and actinoids shown separately?

Placing these 30 elements inside the table would make it very wide, so elements 57 to 71 and 89 to 103 are shown in two rows below.