Giant covalent and Metallic

Types of Giant Ionic Structures

-Diamond

-Silicon dioxide

-Graphite

-Graphene

Draw diamond

Draw silicon dioxide

Properties of giant covalent structures

-High melting point

-Hard

-Good thermal conductors

-Insoluble

Which giant covalent structures can conduct electricity

Graphite/graphene

Which giant covalent structures can’t conduct electricity

-Diamond

-Silicon dioxide

Explain why giant covalent compounds have high melting points

Strong covalent bonds

Explain why giant covalent compounds are hard

Strong covalent bonds

Explain why giant covalent compounds are good thermal conductors

Lattice is stiff, so vibrations travel through them easily

Explain why giant covalent compounds insoluble

No ions and more attracted to neighbours than solvents

Explain why graphite/graphene can conduct electricity whilst most giant ionic compounds can’t

Each carbon forms three bonds, leaving delocalised electrons to carry charge

Draw graphene

Graphite

Layers of graphene held together by weak forces

Metallic bonding

The electrostatic attraction of positive metal ions to delocalised negative electrons

Describe a metallic structure

Lattice of positive ions in a sea of delocalised electrons

Draw the bonding in magnesium

Properties of metals

-High melting point

-Malleable and ductile

-Good thermal conductors

-Good electrical conductors

-Insoluble

Explain why metallic compounds have a high melting point

Strong metallic bonding

Explain whether sodium or magnesium has a higher melting point

Magnesium, as it forms Mg²⁺ ions, unlike Na⁺ ions, so there are more delocalised electrons, increasing the strength of the metallic bond

Explain whether sodium or potassium has a higher melting point

Sodium, as Na⁺ has a smaller ionic radius than K⁺, so the metallic bonds are stronger

Explain why metallic compounds are malleable/ductile

There are no bonds holding ions together, so the layers of metal ions can slide over each other without disturbing the attraction between positive ions and electrons

Explain why metallic compounds are good thermal conductors

Delocalised electrons can pass kinetic energy to each other

Explain why metallic compounds are good electrical conductors

Delocalised electrons are free to move and carry charge

Explain how impurities in metallic compounds affect electrical conductivity

Drastically reduce conductivity, as they remove delocalised electrons to form anions

Explain why metallic compounds are insoluble

Strong metallic bonds