Step by step
- Find the element by its symbol, or type its name in the search box above.
- Read the box: atomic number, symbol, name, atomic mass.
- Tap it to see more: electron configuration, electronegativity, oxidation states, melting and boiling points.
At a glance
| Part of the box | Example (sodium) | Meaning |
|---|---|---|
| Atomic number | 11 | Protons in the nucleus |
| Symbol | Na | From the Latin natrium |
| Atomic mass | 22.990 | Average mass of its atoms (u) |
Related questions
Why are some masses in brackets?
They belong to unstable elements; the value is the mass number of the longest-lived isotope.
What does the color of the box mean?
Its category, such as alkali metal or noble gas; the legend above lists them.
Where are the lanthanides and actinides?
In the two separate rows under the table, to keep it from being too wide.
More questions: periodic table
- How is the periodic table organized?
- What is the periodic table?
- Why is it called the periodic table?
- How many elements are on the periodic table?
- What are the groups on the periodic table?
- Which elements are metals, nonmetals and metalloids?
- What are the periodic table trends?
- Periodic table with charges and oxidation states
- Periodic table electron configuration and valence electrons
- Why is gold Au and potassium K on the periodic table?
- How to memorize and study the periodic table
- Why is the periodic table important?
- Who invented the periodic table?
Open the full periodic table →
Updated November 14, 2026.