Topic 2 - Bonding and Structure Flashcards
(22 cards)
Topic 2: Bonding and Structure
Ionic bond
Strong electrostatic attraction between two oppositely charged ions.
Cation
A positively charged ion, e.g. Na+.
Anion
A negatively charged ion, e.g. S2−.
Isoelectronic species
Chemical species that have the same number of electrons.
Covalent bond
The strong electrostatic attraction between two nuclei and the shared pair of electrons between them.
σ (sigma) bond
A bond that results from a direct (end-on) overlap of two orbitals.
π (pi) bond
A bond that is formed when two orbitals overlap sideways.
Dative covalent bonding
Occurs when one atom donates both electrons in a bond.
Shapes of the molecules
Shapes adopted by the molecules so as to minimise the electronic repulsions.
Allotropes
Different forms of the same element.
Malleable
A malleable substance can be shaped.
Ductile
A ductile substance can be drawn into a wire.
Intermolecular forces
Forces between the molecules.
Electronegativity
The ability of an atom to attract the bonding electrons in a covalent bond.
Dipole
Difference in charge between the two atoms of a covalent bond caused by a shift in electron density.
Metallic bonding
Strong electrostatic attraction between metal ions and the sea of delocalised electrons.
Delocalised electrons
The electrons that are not contained within a single atom or a covalent bond.
Bond length
Internuclear distance between two covalently bonded atoms.
London forces
Weak intermolecular forces arising due to fluctuations of electron density within a nonpolar molecule.
Permanent dipole-dipole interactions
Dipole-dipole attractions between polar molecules.
Hydrogen bond
A type of intermolecular force between a hydrogen and a more electronegative atom like N, O, or F.
