chemical bonding - chapter 4 Flashcards
definitions
ionic bonding
electrostatic attractions between positively and negatively charged ions in an ionic crystal lattice
lattice
a regular repeating arrangement of atoms, molecules or ions.
Van Der Waals’ forces
weak forces of attraction between molecules includes all intermolecular forces
intermolecular forces
the weak forces between molecules
covalent bonding
the electrostatic attraction between the nuclei of 2 atoms and a shared pair of electrons.
lone pair
pairs of electrons in the outer shell of an atom that are not involved in bonding
co-ordinate / dative bond
the sharing of a pair of electrons between 2 atoms where both the electrons in the bond come from the same atom.
bond energy
the energy required to break one mole of a particular covalent bond in the gaseous state.
bond length
the internuclear distance between two covalently bonded atoms
metallic bonding
the electrostatic attraction between positive ions and delocalized electrons.
why is metallic bonding strong?
because the ions are held together by strong electrostatic attraction between their positive and negative charges.
electronegativity
the power of a particular atom that is covalently bonded to another atom to attract a bonding pair of electrons to itself.
what is the trend of electronegativity across a period and down a group?
increases across a period from grp 1 to 17
de creases down a group.
hydrogen bonding (2)
the strongest type of intermolecular force (a type of pd-pd force)
molecules must have a H atom covalently bonded to a highly electronegative atom and another highly electronegative atom with a lone pair of electrons.
what are the 3 peculiar properties of water (caused by h2 bonding)?
- higher enthalpy change of vaporization and boiling point
- high surface tension and viscosity
- ice is less dense than water
hydrolysis
the breakdown of a compound by water/ the breakdown of a substance by acid or alkali
what type of reaction is this :-
SiCl4 + H2O —-> H+ + Cl- + SiO2
hydrolysis
