Periodic Table
Pick any element to see its details. Search by name, symbol or atomic number, or light up a family or block.
Scroll sideways to see the whole table.
Brackets show the mass number of the longest-lived isotope.
About this tool
This interactive periodic table shows all 118 elements, coloured by type. Pick any element to see its atomic number, standard atomic mass (IUPAC values, rounded), group, period, block, electron configuration in shorthand, Pauling electronegativity and its state at room temperature. You can search by name, symbol or atomic number, or light up one family, such as the halogens, or one block at a time.
Tips
- Electronegativity rises across a period and falls down a group, which is why fluorine has the highest value.
- Masses in square brackets belong to radioactive elements. They show the mass number of the longest-lived isotope, not an average.
- Chromium and copper break the usual filling order: they take one electron from 4s to half fill or fill the 3d subshell.
FAQ
- Where do the atomic masses come from?
- They are IUPAC standard atomic weights, rounded to about five significant figures. For elements with no stable isotopes, the value in brackets is the mass number of the longest-lived isotope.
- Why do the lanthanides and actinides sit in separate rows?
- They are the f-block. Putting them inside period 6 and 7 would make the table very wide, so they are drawn underneath. The gaps in group 3 show where they belong.
- Why do some elements have no electronegativity?
- Helium, neon and argon form no compounds, and the heaviest elements have only been made a few atoms at a time, so there is no measured value.