Which of the following period two elements has the highest electronegativity? A) Li, B) Be, C) O, D) C, or E) N.
We can start this question off by just reminding ourselves of the names for these elements, lithium, beryllium, oxygen, carbon, and nitrogen. The term period refers to the periodic table. Period two refers specifically to the second row on the periodic table. So, we can start off this question by locating the five elements in this period. Lithium and beryllium sit to the far left of period two, while carbon, nitrogen, and oxygen sit together on the right-hand side.
Electronegativity is a property of the atoms of an element. And it’s a measure of their ability to attract electrons in bonds. The most common scale for electronegativity is the Pauling scale where elements receive a number between zero and four. High numbers indicate a potent ability to attract electrons in bonds, while a low number indicates a weak ability.
When elements are arranged in the periodic table, there is a general trend, left to right and bottom to top of an increase in electronegativity. On that basis, we would expect lithium and beryllium to have the lowest electronegativities and, out of carbon, nitrogen, and oxygen, for oxygen to have the highest. So, out of the five candidates, the period two element with the highest electronegativity should be oxygen.
If you look up the electronegativity of the elements, you’ll see that our answer is correct. Oxygen has an electronegativity of 3.44, which is higher than all the others. Lithium’s is 0.98. Beryllium is 1.57. Carbon’s is 2.55. And nitrogen’s, the closest, is 3.04. Whichever way we do it, the period two element out of the five given with the highest electronegativity is oxygen.