⚖️ Element Comparison Tool
Pick two to five elements and see their properties lined up in one table — mass, category, configuration, melting and boiling points, density, electronegativity and radius.
| Property | H | Fe | Au |
|---|---|---|---|
| Atomic number | 1 | 26 | 79 |
| Atomic mass (u) | 1.008 | 55.845 | 196.97 |
| Category | Reactive nonmetal | Transition metal | Transition metal |
| Group · Period | 1 · 1 | 8 · 4 | 11 · 6 |
| Block | s-block | d-block | d-block |
| Electron config. | 1s¹ | [Ar]3d⁶4s² | [Xe]4f¹⁴5d¹⁰6s¹ |
| Phase (25 °C) | gas | solid | solid |
| Melting point | 13.99 K (-259.2 °C) | 1811 K (1537.9 °C) | 1337.33 K (1064.2 °C) |
| Boiling point | 20.27 K (-252.9 °C) | 3134 K (2860.9 °C) | 3129 K (2855.9 °C) |
| Density (g/cm³) | 0.00008988 | 7.874 | 19.282 |
| Electronegativity | 2.2 | 1.83 | 2.54 |
| Atomic radius (pm) | 53 | 156 | — |
| Discovered | 1766 | Ancient | Ancient |
Compare up to five elements. Data: IUPAC atomic weights + standard physical properties. 🔒 In your browser.
How the element comparison tool works
Choose the elements you want to compare and the tool builds a side-by-side table of their key properties from the periodic-table dataset — atomic number and mass, category, group and period, electron configuration, phase, melting and boiling points (in K and °C), density, electronegativity, atomic radius and discovery year.
Great for spotting periodic trends — line up elements down a group or across a period and watch electronegativity, radius or melting point change. All data ships with the page.
Frequently asked questions
How do I compare two elements?
Add each element by name or symbol and the tool shows their properties in adjacent columns, so you can read off the differences in mass, electronegativity, melting point and more at a glance.
How many elements can I compare?
Up to five at once — enough to compare a whole group or a stretch of a period.
What properties are shown?
Atomic number and mass, category, group and period, electron configuration, phase, melting and boiling points, density, electronegativity, atomic radius and discovery year.
Can I see periodic trends this way?
Yes — compare elements down a group (e.g. Li, Na, K) to see reactivity and radius grow, or across a period to see electronegativity rise.
Where does the data come from?
IUPAC standard atomic weights and widely cited physical properties (CRC/PubChem). It runs entirely in your browser.