Metallic Bonding
3 marks · Easy| Metal | Group | Ion formed |
|---|---|---|
| Sodium | 1 | Na+ |
| Calcium | 2 | Ca2+ |
| Aluminium | 3 | Al3+ |
Study the table above. For each metal, state how the charge on the ion relates to the number of delocalised electrons present in its metallic lattice.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
Must show: Number of delocalised electrons per atom equals the positive charge on its ion
Also accept: Each sodium atom gives 1 electron, calcium 2, aluminium 3 as delocalised electrons
Common mistakes: Saying there is always 1 delocalised electron; Mixing up delocalised electrons and valency
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States sodium (Na+) gives 1 delocalised electron per atom.
B2 · 1 mark · States calcium (Ca2+) gives 2 delocalised electrons per atom.
B3 · 1 mark · States aluminium (Al3+) gives 3 delocalised electrons per atom.
Worked solution
For sodium (Na+), each atom loses 1 electron, so there is 1 delocalised electron per atom.
For calcium (Ca2+), each atom loses 2 electrons, so there are 2 delocalised electrons per atom.
For aluminium (Al3+), each atom loses 3 electrons, so there are 3 delocalised electrons per atom.