BRAINCAKEPeriod 3 Elements
Period 3 is the third row of the Periodic Table: sodium, magnesium, aluminium, silicon, phosphorus, sulfur, chlorine and argon. Across the period each element has one more proton and one more electron, and the outer electrons fill the 3s and then the 3p sub-level (Na and Mg are s-block; Al to Ar are p-block).
The structure and bonding of the elements changes across the period:
• Na, Mg and Al are metals with metallic bonding (a lattice of positive ions in a sea of delocalised electrons).
• Si is macromolecular (giant covalent), like diamond.
• Phosphorus (P4), sulfur (S8) and chlorine (Cl2) are simple molecular, with weak van der Waals forces between the molecules.
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More in Period 3 Elements and Oxides
- Reactions of Sodium and Magnesium with Water
- Reactions of Period 3 Elements with Oxygen
- Period 3 Oxides
- Melting Points of Period 3 Oxides
- Reactions of Period 3 Oxides with Water
- pH of Period 3 Oxide Solutions
- Acid-Base Character of Period 3 Oxides
- Amphoteric Aluminium Oxide
All 10 lessons in Period 3 Elements and Oxides · All AQA A-level Chemistry topics