Bonding Flashcards
What is ionic bonding
Strong electrostatic forces of attraction between oppositely charged ions held in a lattice
Ionic bp
High because takes a lot of energy to break strong electrostatic forces of attraction between oppositely charged ions
Do ionic compounds conduct electricity
Yes when molten as ions are free to move
What is simple molecular covalent bonding
Strong covalent bonds between atoms, weak van der waals forces of attraction between molecules
Can simple molecular covalent molecules conduct electricity
No, no electrons free
So simple molecular substances have a high or low bp
Low
Weak van der waals forces of attraction between molecules that don’t take much energy to overcome
Describe macromolecular covalent bonding
Lattice of many atoms held together by strong covalent bonds
So macromolecular covalent bonds have high or low bp
High
As it takes a lot of energy to overcome strong covalent bonds
Metallic bonding
Lattice is positive metal ions strongly attracted to a sea of delocalised electrons
Do metallic compounds have a high or low bp
High
Strong forces of attraction between positive ions and negative electrons
Do metallic compounds conduct electricity
Yes as delocalised sea is electrons
Define electronegativity
The ability of an atom to attract the pair of electrons in a covalent bond
What affects electronegativity
Nuclear charge
Atomic radius
Electron shielding
What is the most electronegative element
F
How do you get a non polar bond
Both bonding elements have the same electronegativities
What is the strongest intermolecular force
Hydrogen bonding
What is the weakest intermolecular force
Van der waals
Describe van der waals
Temporary dipoles are created by the random movement of electrons
Induces dipole in neighbouring molecule
Temporary induced dipole dipole
Describe permanent dipole dipole
Some molecules with polar bonds have permanent dipoles
Forces of attraction between those dipoles and those of neighbouring molecules
What conditions are needed for hydrogen bonding
O N F are highly electronegative
Strong attraction between H nucleus and lone pair of electrons on O N F
Why is ice less dense than liquid water
In liquid hydrogen constantly break and reform
In ice the hydrogen bonds hold the molecules in fixed positions this makes them slightly further apart than in liquid
What is co ordinate bonding
Formed when an electron deficient atom accepts a lone pair of electrons from an atom with a lone pair of electrons
What does the shape of molecules depend on
Number of electrons on the valence shell
Number of these electrons which are in bonded or lone pairs
