simple covalent structure and metallic structures

What are layers of I2 held by?

weak inter molecular forces - I2 held by covalent bonds

Why is ice less dense than water?

strong intermolecular forces mean that the H₂O molecules in ice form a tetrahedral structure that is both rigid and spaced out. - takes up greater volume

what are the similarities in water and iodine? (simple covalent structure)

• low melting point - weak intermolecular forces

• soft

• electrical insulators - lack of any mobile charged molecules

What is the structure of metallic structures?

• meal cations (positive) closely packed surrounded by sea of delocalised electrons

How does the sea of delocalised electrons form?

e valence electrons (i.e., outer electrons) are so weakly bound to their atoms that these electrons can move freely throughout the lattice of metal ions.

how are metal ions held together?

electrostatic attraction between electrons and metal cations

What are properties of metals?

• good conductors of heat and electricity

• malleable - shape permanently without breaking

Why are meta good conductors of heat?

• delocalised electrons carry energy

Why are metals malleable?

• layers can slide over each other - delocalised electrons move with ions to maintain bonding

How is the hardness of metal and the boiling and melting point determined?

• more delocalised electrons - more hard / high melting / boiling point