How can you tell if a compound has an ionic bond, polar covalent bond, or a non-polar covalent bond?
1 Answer
If the difference of the electronegativity between the two elements is greater than 1.7 then the bond is ionic. The difference with a polar covalent bond is 0.5 to 1.7 and a nonpolar covalent bond is from 0 to 0.4.
Explanation:
The number 1.7 in the difference between electronegativity of two elements in a compound is subjective as some textbooks go all the way up to 2.2.
Secondly, electronegativity is the number assigned to atoms of a specific element that goes from 0 to 4 and expresses how strongly that atom wants another electron.
In an ionic molecule, the electron(s) spend all of its time with the atom with the higher electronegativity.
In a polar covalent bond the two atoms are sharing the electron but it spends a greater portion of its time with the atom that has the higher electronegativity (the atom whose electronegativity is higher by 0.5 to 1.7).
In a nonpolar covalent bond the two atoms are sharing the electron basically or totally equally, meaning that even when the difference is not 0 (which can happen with molecules that are composed of the same element, such as I2 or 02) the electron does not spend a perciptibal amount of time at one or the other.
