Metal atoms give up their outer electrons, but not to anyone in particular. The electrons spread through the whole lattice and glue the positive ions together, which is why metals conduct, bend and shine.
Metallic bonding is the electrostatic attraction between positive metal ions and delocalised electrons. The outer electrons of each atom are released into a “sea” that belongs to the whole giant lattice. The bonding gets stronger as more electrons per atom are delocalised, as the ionic charge rises and as the ions get smaller, so melting points rise from sodium to magnesium to aluminium. The mobile electrons carry current and heat, and because the bonding is non-directional the layers of ions can slide without the lattice breaking.
Choose sodium, magnesium and then aluminium in the simulator. Count the delocalised electrons each atom contributes and watch how tightly the lattice holds together as that number rises.
| Metal | Ion | Delocalised electrons per atom | Melting point / °C |
|---|---|---|---|
| sodium | Na+ | 1 | 98 |
| magnesium | Mg2+ | 2 | 650 |
| aluminium | Al3+ | 3 | 660 |
Across Period 3 the ions become smaller and more highly charged while the sea becomes denser, so the attraction gets stronger. Down Group 1 the ions get larger with the same charge, so the melting point falls: Li 181 °C, Na 98 °C, K 63 °C.
Every classic metal property traces back to electrons that are free to move and bonding that has no fixed direction.
Four quick checks. Each correct answer earns XP and records this skill on your profile.
Metallic bonding is the attraction between:
How many electrons per atom does magnesium contribute to the delocalised sea?
Why do metals conduct electricity when solid?
Why can metals be hammered into shape without breaking?
Both are giant lattices held by electrostatic attraction, so students often mix them up. The difference is what the positive ions are attracted to.
| Metallic | Ionic | |
|---|---|---|
| particles | positive ions and delocalised electrons | positive and negative ions |
| solid conducts? | yes, electrons move | no, ions fixed |
| when hit | bends: layers slide | shatters: like charges meet |
Say positive ions in a metal lattice, not atoms, and describe the electrons as delocalised. Answers that describe “metal atoms sharing electrons” or “ions attracting each other” do not score: the bond is ion to electron sea.
Unlocks once the four checks above are done. Worth more XP, written to AS Paper 1 and Paper 2 standard.
Which metal is expected to have the highest melting point?
The melting points of the Group 1 metals decrease from lithium to caesium because:
Which statement correctly compares solid copper and solid sodium chloride?
Which description of the metallic lattice is correct?
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