Structure and Bonding Flashcards
What type of bonding is present in diatomic elements?
Pure covalent.
What kind of elements form a pure covalent bond?
Those with equal electronegativity
What kind of elements form a polar covalent bond?
Those with a small difference in electronegativity, typically 0.5-1.5.
What kind of elements form a ionic bond?
Those with a large difference in electronegativity, typically >1.5.
In a pure covalent bond how are the electrons shared?
Equally.
What is the sharing of electrons like in a polar covalent bond and what arises from this?
There is unequal sharing of electrons. The atom with the higher electronegativity attracts the electron more strongly than the other atom and so the atom with higher electronegativity gains a slightly negative charge and the atom with lower electronegativity gains a slightly positive charge, these are known as a dipoles.
What is the sharing of electrons like in a ionic bond and what arises from this?
There is no sharing of electrons in a ionic bond, it occurs where electrons are transferred from the atom with lower electronegativity to the atom with higher electronegativity. This results in the lower electronegativity atom losing an electron and gaining a slightly positive charge and the higher electronegativity atom gaining an electron and a negative charge.
What kind of elements does ionic bonding normally occur between?
Metal and non-metal.
How does one distinguish between ionic and covalent bonding?
Ionic Compounds will conduct electricity when in solution
Ionic compounds tend to have higher MP due to the high energy required to break ionic bonds in an ionic lattice
Ionic compounds tend to be soluble in water
What are the three types of intermolecular forces
London Dispersion Forces
Permanent dipole-permanent dipole interactions
Hydrogen Bonding
What kind of molecules have LDFs?
All molecules.
What kind of molecules have Permanent dipole-permanent dipole interactions
Polar molecules
In what molecules does hydrogen bonding occur?
Polar molecules where a H atom is bonded directly onto a F, O, or a N
How do LDFs arise?
The temporary uneven dispersion of moving electrons
Explain how LDFs arise?
The temporary uneven dispersion of moving electrons causes one side of an atom to have a deficiency of electrons and one side to have a excess of electrons. This causes a dipole to form, this causes an induced dipole to form in a neighboring atom and a electrostatic attraction between the temporary and induced dipole of neighboring atoms.
