Tool 04
Pick two to four elements and read their properties side by side. Every bar is scaled against all 118 elements, so an unusual value stands out at a glance.
Free, no account, and nothing you type leaves your browser.
Pick up to four. Every bar is scaled against all 118, so you can see at a glance which is the outlier.
| Property | Na | K |
|---|---|---|
| Atomic radius pm | 186 | 227 |
| Ionisation energy kJ/mol | 495.9 | 418.7 |
Down group 1 the outer electron sits farther from the nucleus: potassium has the larger atomic radius and the lower first ionisation energy.
Open this example in the tool| Property | F | Cl |
|---|---|---|
| Electronegativity | 3.98 | 3.16 |
| Electron affinity kJ/mol | 328 | 348.3 |
Fluorine is the most electronegative element, yet chlorine releases more energy when it gains an electron: its electron affinity is higher.
Open this example in the tool| Property | Cu | Ag | Au |
|---|---|---|---|
| Density g/cm³ | 8.96 | 10.501 | 19.32 |
| Ionisation energy kJ/mol | 745.8 | 731.4 | 890.6 |
Density rises down group 11, but gold breaks the trend in ionisation energy: relativistic effects pull its outer 6s electron closer to the nucleus, so removing it takes more energy than for silver.
Open this example in the toolValues come from the same element data as the rest of the site. Each bar shows where a value falls between the lowest and the highest among all 118 elements, so a short bar means low for the whole table, not just among your picks. The highlighted value in each row is the highest of the elements you chose.
Below the numbers, text rows compare family, block, period and group, electron configuration, oxidation states and year of discovery. Each element links to its own page.
Grams per mole and percent composition for any formula, ion or common substance name.
OpenBalances molecular, ionic and redox equations exactly, with an atom and charge check.
OpenFull and noble-gas notation and an orbital diagram for all 118 elements, plus a trainer.
OpenTemperature, energy, pressure, moles and atomic lengths, with exact SI constants.
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