SME
Grade 10 Science · Problem type
Metallic bonding: a sea of electrons
Use this for metallic bonding: how many electrons a piece of aluminum shares among its ions.
Diagram
Each aluminum atom gives its 3 valence electrons to the whole piece: 6 × 3 = 18 electrons.
They move freely among the positive ions (a sea of electrons), so metals conduct and bend without breaking.
This is an example. Type your own values to start a new problem.
e
=
3
×
n
Formulas
e
=
3
×
n
18 = 3 × 6
Assumptions
•
Each aluminum atom gives up its 3 valence electrons to the whole piece of metal.
•
The electrons move freely among the ions, so metals conduct electricity.
•
The ions can slide past each other without breaking the bond, so metals bend instead of shattering.
Step-by-step
WE KNOW
n = 6
FIND
free electrons (e)
Step 1 · Find free electrons (e)
Use e = 3 × n
Each atom gives 3 electrons to the sea.
e
=
3
×
6
e
=
18
Check
Put the numbers back in. Both sides should match.
18 = 3 × 6 ✓
Topic check
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Related lessons
Ionic, covalent and metallic bonding
Main lesson
The formula of an ionic compound
Use this to find an ionic compound’s formula from the charges of its ions: Mg²⁺ with Cl⁻ is MgCl₂, Al³⁺ with O²⁻ is Al₂O₃.
Bond polarity from electronegativity
Use this to tell whether a bond is nonpolar, polar covalent or ionic from the electronegativity difference.
Properties of ionic, molecular and metallic substances
Use this for “Which observation shows that a solid is an ionic compound?”
Ionic, covalent or metallic?
Use this for “What kind of bond holds magnesium oxide together?”