Bonding Flashcards
Definition of Electronegativity
“the ability of an atom to attract the bonding electron pair in a covalent bond to itself.”
Ionic Bonding Definition
“an ionic bond is the electrostatic attraction between oppositely charged ions. It is formed by the transfer of electron(s).”
Metallic Bond definition
“attraction between the orderly arrangement of positive metal ions and the moving valence electrons.”
or
“lattice of positive metal ions embedded in a sea of valence electrons.”
Covalent Bond Definition
“consists of a shared pair of electrons with one electron being supplied by each atom either side.”
Hydrogen Bonding Definition
“hydrogen bonds occur when H is covalently bonded to the 3 most electronegative atoms (FON) - the dipole is so great that the strong attractions are set up to the lone pairs on F,O or N atoms on neighbouring molecules.”
London Dispersion Forces Definition
are the movement of electron clouds
an instantaneous dipole is created which then induces a dipole in the neighbouring molecules
Dipole Dipole Forces Definition
are an electrostatic attraction which is formed by the separation of charge (polar molecules)
Resonance Definition
“resonance occurs when there is two or more Lewis Structures to represent a particular molecule or ion. They occur when there is more than one possible position for a double bond in a molecule.”
Hybridisation Definition
“results from the mixing of atomic orbitals to form the same number of new equivalent hybrid orbitals that have the same mean energy as the contributing orbitals.”
Sigma Bond Definition
form by the direct head - on (end to end) overlap of atomic orbitals, resulting in electron density concentrated between the nuclei of bonding atoms.”
Pi Bonds Definition
formed by the sideways overlap of p atomic orbitals, resulting in electron density above and below the plane of the nuclei bonding atoms.
Delocalisation Definition
when a molecule or ion has more than two atoms, the pi electrons are spread over more than two nuclei, they are mobile and shared by a number of atoms.
This spreading out of electrons gives the species a lower potential energy making it more stable than if it were composed of a simple double and single bond.
What elements form ionic bonds?
elements with low electronegativity will form ionic bonds with elements of high electronegativity
What elements form covalent bonds?
elements with moderate to high electronegativity form covalent bonds with each other
(where the elements are different, the more EN one will carry the partial negative charge resulting in a polar covalent bond)
What elements metallic bond?
elements of low electronegativity (metals) form metallic bonds (alloys)
