Is there any way I can differentiate electrical conductivity?

[girlbythewindow]

...Kay, so I was doing [or trying to do] my homework, and it's pretty basic, actually.
We're given a table comprising substances like "vegetable oil", "gatorade", "pencil lead", etc; and asked to predict its electrical conductivity.

I tried Googling some of it, but nothing really relevant actually came up.

I get the part that electrolytes are mainly solutions of acids, salts, and bases...but my question is: for substances like vegetable oil, how can you tell its electrical conductivity?

...Also, if I have a salt in solid form, will it conduct electricity as well?

 

[Astronuc]

It depends on the types of bonds in the material - metal, ionic, covalent. Metals have highly mobile electrons, ionic solids less so, and covalent bonds much less.

What happens in an electrolyte?

What types of bonds are found in vegetable oil?