Bonding 3 Flashcards
(46 cards)
Positive and negative ions are formed
Ionic
Ionic lattice
Electrostatic forces between oppositely charged ions.
Two non-metals
Covalent
Share their electrons
Covalent
Dative covalent bonding
Atom that accepts the electron pair is an atom that doesn’t have a filled outer main shell ( electron-deficient)
Atom that is donating the electron has a pair of electrons (lone pair)
(contains a shared pair of electrons with both electrons supplied by one atom)
Delocalised electrons
Metallic bonding
Good conductors of heat and electricity
- sea of delocalised electron
- high thermal conductivities
Strength of metals
- charge of ions
- size of ion
Malleable and ductile
Layers can slide over each other
High melting point
Giant structure
Strong attraction between metal ions and sea of delocalised electrons
Electronegativity
The power of an atom to attract the electron density in a covalent bond towards itself
(Electronegativity as the power of an atom to attract the pair of electrons in a covalent bond)
What element is the most electronegative?
Fluorine
Metal and non-metal
Ionic
Polar
Greater the difference in electronegativity the more polar the bond is
Metallic bonding
(Metallic bonding involves attraction between delocalised electrons and positive ions arranged in a lattice)
Positive metal ion and an electron
Sea of delocalised electrons
Ions ( and electrons) repel each other
Good conductor of heat and electricity
Strength
Increase charge of the ion
Malleable and ductile ( layers slide over each other)
High melting point
Ionic bonding
Electrostatic attraction between oppositely charged ions ( creates a ion lattice )
Giant structures - high melting point
Conduct electricity
Brittle and shatter ( small displacement causes two positive ions ( or electrons) to touch each other and repel each other
Covalent bonding
Pair of electrons are shared
Strong covalent bonds are only between the atoms with in the molecule
Weak attraction between molecules so not much energy is needed
Poor conductor
Co-ordinate bonding
Covalent bonding in which both the electrons in the bond come from one of the atoms in the bond
One of the atoms would have a lone pair
Represented by an arrow
Electronegatively increases across a period
Increased nuclear charge
Amount of shielding stays the same
Atoms are smaller because the positive charge makes in smaller
Electronegatively decrease down a group
More distance from the nucleus
Amount of shielding increases
Nuclear charge increases but is counteracted by the shielding effect and distance
Van der waals
At any time the electrons can be anywhere. At any moment it could have a dipole at any time
Closer together the molecules the stronger the force
Larger molecules have larger electron clouds meaning stronger van der waal force
Dipole-dipole
Permeant dipole ( one is positives and one is negative)
Opposite charges attract and repel each other
Hydrogen bonding
Fluorine
Oxygen
Nitrogen
Very electronegative
Importance of hydrogen bonding
Molecules are slightly less closely packed than a liquid so it is less dense than water
Forms on top of ponds
Insulates ponds
