U.C.Berkeley
M.Ed.,San Francisco State Univ.
Jonathan has been teaching since 2000 and currently teaches chemistry at a top-ranked high school in San Francisco.
Here are some tips and tricks for determining bond type without looking at the electro negativity values. If you have a periodic table, and I’ll just draw a sketch. You don’t have to draw it out of course. Then the periodic table looks more like this. And so pretty easy. There are 3 bond types.
There is nonpolar covalent, and that type of bond would be found when I have 2 atoms of the same element. That’s pretty easy. So say if I have a Fluorine – fluorine bond, that would be nonpolar covalent. Or say if I have an Oxygen – Oxygen bond that will be non polar covalent. So two atoms, same element, non polar covalent. You don’t even need to look at the electro negativity values.
Then for polar covalent, which is the second type. If I generally have 2 non-metals but they’re different elements, then I would have polar covalent. Or if I have in general hydrogen and a non-metal, then that would be polar covalent. An example could be like say if I have a Nitrogen – Oxygen bond, that’s 2 non-metals, different elements, so that would be a polar covalent bond. If I have say H - F, the H – F is Hydrogen and also a non-metal. So that would be polar covalent.
The third is ionic. You can generalize it by saying, if you have a bond between a metal and a non-metal, then you would have an ionic bond usually. So 95% percent of the time, 99% of the time it would be. Let’s say if I had Na and F or let’s say if I had Zn and F. If I had those, so in general a metal and a non-metal, it would help you out. Without even figuring out the electro negativity, you can kind of look at the periodic table.
The further apart they are in the periodic table, this would be an ionic bond. If they’re close together on the periodic table, like say here and here, then this would be polar covalent, because those are both non-metals. If it’s the same one, the same element, then obviously it would be nonpolar covalent. So like F – F, O – O or N – N or H – H. Any of those.
Hopefully these short-cuts help you in determining the type of bond. Nonpolar covalent, polar covalent or ionic. Have a good one.
