posted by maria .
Using electronegativity arguments, classify the following diatomic molecules as nonpolar (N), polar (P), or ionic (I), and enter five letters in order (e.g. NPNPI, INPNP, etc) : NaF, HF, NaH, CaO, and F2.
Look up electronegativity (EN)of each element and subtract to obtain a delta EN for the compound. I don't know what you teacher is using for a cut off point but I use 2.1 or so. Use what your teacher recommends. Above that value is ionic. Zero is non-polar. Between those two values is polar. Delta EN for F2, of course, is zero so that is N. CaO is 3.5 - 1.0 = 2.5 = ionic. Etc.