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How do potassium’s melting and boiling points compare with those of lithium and cesium?

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A periodic table element box for potassium shows atomic number 19, symbol K, atomic weight 39.0983, electron configuration [Ar]4s1, and name potassium. Icons indicate it is an alkali metal, solid at room temperature, body-centered cubic crystal structure, and has strongly basic higher-valence oxides. A key explains the symbols for alkali metals, solid state, body-centered cubic structure, and strong basicity. — potassium Properties of potassium.

Potassium's melting and boiling points fall between those of lithium and cesium, following the general trend where these values for alkali metals decrease as atomic number increases.1

The following table compares these physical properties:

| Element | Melting Point (°C) | Boiling Point (°C) |
| :--- | :--- | :--- |
| Lithium | 180.512| 1,34212|
| Potassium | 63.381| 7591|
| Cesium | 28.4413| 67113|

As shown, lithium has the highest melting and boiling points of the three, while cesium has the lowest. The relatively low melting points of these elements are a direct result of the large interatomic distances in their crystals and the weak bond energies associated with such loose arrays.1