chemistry??

Question

How does unequal sharing of electrons occur, and how does it affect molecules?

How are the formulas and names of ionic compounds written?

Please help! I have a quarterly 2morrow and it counts as 2 tests!!!

Answer 1

Unequal share leads to a polar molecule
like water H2O this occurs when one element desires electrons more than the other

Answer 2

Atoms of the elements have different electronegativities, which means that they have different affinities for the electrons shared between them in chemical bonds. Atoms with greater electronegativities like fluorine (4.0), oxygen (3.5), and nitrogen and chlorine (both 3.0) take the greater share of electrons and so take on a small minus (-) charge in covalent bonds. When they combine with elements of lesser electronegativities, the other elements take on a slight (+) charge.

Water, H-O-H, is case in point. It is shaped like a boomerang. The (-) head is the O, and the two (+) H's are the tail. Each (+) H of one molecule has an attraction for the (-) O of another. So water has an enormously high boiling point of 100C and a very high freezing point of 0C. It also has large latent heats of fusion and vaporization, as well as heat capacity.

One writes names of compounds with the (+) cation metal first and the (-) anion non metal second. In the case of two oxidation states, CuO is cupric oxide or copper(II) oxide, while FeO is ferrous oxide or iron(II) oxide. Anions take the suffixes -ide, ite, -ate, depending on the oxidation state. It gets worse than that: There are hypo- and per- prefixes on top of that.