intermolecular forces Flashcards
(14 cards)
what is electronegativity?
the tendency of an atom to attract a bonding pair of electrons
how does an atoms electronegativity change down a group?
it decreases
how does an atoms electronegativity change across a period?
it increases
what does a higher electronegativity mean?
a stronger pull on shared electrons
what happens if atoms have similar electronegativity?
form covalent bonds
what is a non polar molecule?
atoms that have the same electronegativity so the electron is distributed evenly (H2 or N2)
what is a polar molecule?
when atoms have different electronegativities so one atom pulls the electron more than the other eg Cl and H they will become more negatively charged than the other
what happens to the other atom when one atom has a higher electronegativity?
dipole temporarily- becomes slightly positively charged as the electron is further away
what are intermolecular forces?
the attraction or repulsion between neighbouring molecules
what are the 3 types of intermolecular forces?
van der waals, dipole dipole and hydrogen
what is a van der waal force?
weak forces that are present between non-polar covalent molecules ( negative and positive slight charge from e- pull)
