And that means as we go from lithium to beryllium, to boron, to a carbon to nitrogen to oxygen, finally, to fluorine our electronegativity increases, and in fact, fluorine is the most electronegative atom and electronegativity is actually measured on a scale called the polling scale, and it's given a highest value of 4.0. Now, as we go across the period from left to right, we see that our electronegativity increases how about as we go from top to bottom? Well, as we go from top to bottom, our atomic radius increases. So our force with which our protons in the nucleus pull those electrons decreases. Because remember, force, according to Coulomb's law, is equal to K times q one times q two over r two. So our denominator increases, decreasing our force.