Lithium vs Cobalt
Lithium is a metal (alkali metal); Cobalt is a metal (transition metal).
The differences in plain English
- Both are solids at room temperature.
- Cobalt is denser, about 16.7 times more than Lithium (8.9 against 0.534 g/cm³).
- Cobalt melts at 1495 °C, far above Lithium at 180 °C.
- An atom of Cobalt is about 8.5 times heavier than an atom of Lithium (58.93 u against 6.94 u).
- Cobalt pulls electrons more strongly in a bond (electronegativity 1.88 against 0.98).
Side by side
| Lithium | Cobalt | |
|---|---|---|
| Atomic number | 3 | 27 |
| Symbol | Li | Co |
| Family | Alkali metal | Transition metal |
| Group / period | 1 / 2 | 9 / 4 |
| State at room temperature | Solid | Solid |
| Atomic mass | 6.940 u | 58.933 u |
| Density | 0.534 g/cm³ | 8.9 g/cm³ |
| Melting point | 180 °C | 1495 °C |
| Boiling point | 1330 °C | 2927 °C |
| Electronegativity | 0.98 | 1.88 |
| First ionisation energy | 520.2 kJ/mol | 760.4 kJ/mol |
| Electron configuration | [He] 2s1 | [Ar] 3d7 4s2 |
| Discovered by | Johan August Arfwedson | Georg Brandt |
Lithium
Lithium is a soft, silvery metal and the lightest solid element. A lump of it feels oddly weightless in the hand, with roughly half the density of water. It is the first of the alkali metals, the family that fills the left-hand column of the periodic table and reacts eagerly with water.
- Lithium is the lightest metal and the least dense solid element.
- Lithium was one of only three elements created in significant amounts in the Big Bang.
Cobalt
For most of history cobalt meant one thing: blue. Cobalt compounds gave Egyptian glass, Persian tiles, Chinese porcelain and Dutch Delftware their deep blue colours long before anyone knew the metal existed. Today cobalt has a very different reputation, as the critical metal in rechargeable batteries, jet engines and cancer treatment, and as a metal whose mining raises hard ethical questions.
- Cobalt, isolated in 1735, was the first metal to be discovered since ancient times.
- Vitamin B12 is the only vitamin that contains a metal atom, a single cobalt at its centre.
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More comparisons
Read more about each element
Lithium belongs to the alkali metals and Cobalt to the transition metals. See all element comparisons or browse all 118 elements.
Data from Periodic-Table-JSON (CC BY-SA); temperatures rounded to the nearest degree. Written by Anthony. Published September 2026.