How is electronegativity used to determine bond polarity

The greater the difference in electronegativity is the more polar the bond is.

Explanation:

If an atom or molecule is electronegative it means it strongly attracts the electrons of an atom while in a bond. So if you have on highly electronegative element and one not so electronegative element, the more electronegative element will attract electrons stronger, giving it a slightly negative charge, while the other end will have a slightly positive charge. This creates a polar bond. However, if there are similar electronegativity then both atoms will attract electrons equally creating a non-polar compound. This is common in when identical atoms bond. But, a compound can have polar bonds but still be non-polar. For example, carbon dioxide (CO2). The carbon is in the middle and oxygen, the more electronegative are on both sides pulling the electrons. This cancels out and creates a non-polar compound.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.