A1: Bonding Flashcards
Define ionic bonding
The electrostatic attraction between positive and negative ions
Melting/Boiling point of Ionic compounds
High, due to the strong electrostatic forces (which are even higher for ions with higher charges)
Define covalent bonding
Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
What is a dative covalent bond
A covalent bond in which the shared pair of electrons have both been supplied by one of the bonding atoms - the shared electron pair was initially a lone pair
Define metallic bonding
Strong electrostatic attraction between cations and delocalised electrons
Properties of metals
High electrical conductivity (delocalised electrons are free to move and carry a charge), high MP and BP, don’t dissolve
Giant covalent structures melting and boiling points
High as covalent bonds are strong
Are giant covalent structures soluble?
No they are insoluble as covalent bonds are too strong
Do giant covalent structures conduct electricity?
They are non conductors, except for graphene and graphite, where one electron per carbon is available for conductivity
Do ionic compounds dissolve?
Many dissolve - water molecules break down the lattice structure and attract and surround the ions.
Ionic compounds with large charges don’t dissolve as the water cannot break the structure.
Can ionic compounds conduct electricity?
No when solid as no mobile charge carriers.
Yes when molten or dissolved as the ions are free to move and carry a charge.
Graphene and Graphite
Graphene - a single layer of graphite, each carbon makes three bonds, hexagonal structure, thinnest and strongest metal
Graphite - parallel layers of graphene, layers bonded by weak London forces
