Structure and Properties of Diamond, Graphite, Silica, and Related Bonding Concepts

Vocabulary flashcards covering bonding structures and physical properties of diamond, graphite, silica, and related bonding concepts.

Diamond

A giant covalent structure where each carbon atom forms four strong covalent bonds (tetrahedral), giving it extreme hardness, very high melting/boiling points, and no electrical conductivity.

Graphite

A form of carbon in which each atom is covalently bonded to three others, creating layers of hexagonal rings with delocalised electrons that allow electrical conductivity; layers are held together by weak forces and can slide, making it soft.

Delocalised Electron (in graphite)

An electron not bound to a single atom or bond, free to move between layers in graphite, enabling it to conduct electricity.

Polar Covalent Bond

A covalent bond involving an unequal sharing of electrons between atoms, creating partial positive and negative charges.

Ionic Compound (electrical conductivity)

A substance that conducts electricity only when molten or dissolved, because ions are free to move in the liquid state.

Silica (Silicon Dioxide)

A giant covalent network of silicon and oxygen atoms found in sand and glass, noted for its hardness and very high melting/boiling points.

Weak Intermolecular Forces in Graphite

Van der Waals forces between graphite layers; they are easily overcome, allowing the layers to slide past one another.

Tetrahedral Bonding in Diamond

The arrangement in diamond where each carbon atom forms four sp³ hybridised bonds oriented at 109.5°, creating a rigid three-dimensional lattice.

Trigonal Planar Bonding in Graphite

The arrangement in graphite where each carbon atom forms three sp² hybridised bonds at 120°, lying in a plane to create hexagonal sheets.