An interactive periodic table with all 118 elements, their standard atomic weight, electron configuration, electronegativity, melting and boiling points and who discovered them. Search by name, symbol or number, and colour the table by category, state or block. It is free, with no ads and no sign-up.
How to use the table
- Type a name, symbol or atomic number into Find an element.
- Click or tap any element, or use the arrow keys to move around the table, to see its details.
- Use Colour by to switch between Category, State at 20 degrees C and Block.
- Choose Kelvin, Celsius or Fahrenheit under Temperatures to read melting and boiling points your way.
Reading the table
Rows are periods: each new row starts a new electron shell. Columns are groups, and elements in the same group behave alike because their outer electrons match, which is why sodium and potassium both react with water. The two rows below the table are the lanthanides and actinides, which belong in period 6 and 7; they sit apart only so the table fits on a page.
Where the numbers come from
Atomic weights are the IUPAC abridged standard atomic weights. A number in brackets, like [97] for technetium, means the element has no stable isotopes and shows the mass number of its longest-lived isotope instead. Electronegativity uses the Pauling scale. Melting and boiling points are at normal atmospheric pressure. For the heaviest elements only a few atoms have ever been made, so most of their properties are unknown, and their electron configurations are predictions.
Search and colours
Type a name, a symbol or an atomic number to pick out an element, or a word like “noble” or “halogen” to light up a whole family. Colour by state to see the two elements that are liquid at room temperature, bromine and mercury, or by block to see how the s, p, d and f orbitals shape the table.
Using it for study
- Learn the groups by colouring by category and noticing which families sit together.
- Look up an electron configuration when you are writing out an atom or an ion.
- Compare electronegativity across a period to see how bonds change.
- Check an atomic weight before a calculation, then use the molar mass calculator for whole formulas.
Questions
How many elements are there?
The table shows all 118 named elements.
Why is an atomic weight in brackets?
The element has no stable isotopes, so the number shown is the mass number of its longest-lived isotope.
Which two elements are liquid at room temperature?
Bromine and mercury. Colour by state to see them.
Can I use it on a phone?
Yes. Tap an element to see its details.