Question

How can you determine the polarity of chemical compounds?

Answer 1

examine the theoretical model of the chemical molecules,
asymmetricness can give rise to polarity

Answer 2

Do I determine this using the number of valence electrons?

Answer 3

yeah that part of the theory will determine the angles between the atoms in the molecule, this is essentially what gives the molecule its shape

Answer 4

So if the amount of electrons subtracted from each chemical isn't 0, then the compound is polar, but if the amount of electrons does subtract to 0 then the compound isn't polar?

Answer 5

not exactly
For example starting with a chemical formula \[H _2 O_{(l)}\]
which is electrically neutral
We find two covalent bonds between the central oxygen and adjoining hydrogen

Answer 6

However oxygen in in the the VI column of the PT, suggesting that it has 6 electrons (3 electron pairs) in its outer shell + the two covalently shared electrons. So we have 8 electron , a that is 4 pairs . sticking in four points onto a sphere each as far way for each other as possible (electron pairs are repelling each other ), geometry gives us the angle (104.45°)

Answer 7

This is a drawing of the molecule
it is clearly not spherically symmetric
infact one side has greater electron density than the other ,