Melting points of elements
Hovering above a point will show the atomic number and the melting point (MP) of the element.
Melting point trends in the Periodic Table
The element with the highest melting point of 3,500°C is Carbon (N=6).
The Noble gas elements in Group 18 (He, Ne, Ar, Kr, Xe, Rn) have the lowest melting points due to the weak London dispersion forces between their atoms.
While there are exceptions, a general trend can be observed for melting points across a period (row of table).
Across a period, the melting points generally increase from left to right, reaching a peak around group 6 (Tungsten, Molybdenum, Chromium) and then decrease.
In the Periodic Table groups (columns), there is no uniform pattern (see Table 1). In Groups 2 & 3, melting points decrease down a group. In groups 4-10 melting points increase down a group. In groups 16-18 melting points increase down a group (see Table 1).
| Period | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Trend | ↑ | ↓ | ↓ | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ | − | ↓ | ↓ | ↓ | − | ↑ | ↑ | ↑ |
Legend for the Table 1 values:
↑: Values increase down a group; ↓: Values decrease down a group.
Metals:
Metallic bonding involves a lattice of positive ions surrounded by a sea of delocalized electrons. Across a period, the number of delocalized electrons increases, strengthening the metallic bond and leading to higher melting points. Down a group, atomic size increases, weakening the metallic bond and leading to lower melting points.
Non-metals:
Non-metals form covalent bonds, which are generally weaker than metallic bonds.Melting points of non-metals are generally lower than those of metals. There's less of a clear trend across a period or down a group for non-metals due to variations in molecular structure and intermolecular forces.
Exceptions to the Trend:
Transition metals: Some transition metals exhibit irregularities in melting points due to factors like electron configuration and crystal structure.
The trends in melting points are general guidelines and there are many exceptions. The specific melting point of an element is influenced by various factors, including atomic size, electron configuration, and crystal structure.