From their positions in the periodic table, which of the following has the lowest electronegativity? A) Sr, B) Ge, C) S, D) B, or E) N.
Before we really get started with this question, let’s make sure that we know the names for the elements with these symbols. We have strontium, Sr, germanium, Ge, sulfer, S, boron, B, and nitrogen, N. Now, let’s find where they sit in the periodic table.
Here we have our periodic table. Now, let’s find the first element. Strontium is in group two and period five. It’s an alkaline earth metal. Germanium is in period four and in group 14, sometimes called group four. Germanium sits below silicon and carbon. Sulfer can be found in period three in group 16, otherwise called group six. It could be found below oxygen and just to the left of chlorine. You can find boron in period two and group 13, otherwise called group three. An atom of boron has three electrons in its outer shell. And last of all, we have nitrogen in period two and group 15, otherwise called group five. Our job is to look at their positions on the periodic table and assess which one is likely to have the lowest electronegativity.
Electronegativity is a property of an element and its atoms. It’s a measure of the ability of those atoms to attract electrons in bonds. The most popular scale for electronegativity is the Pauling scale, which places each element on the scale between zero and four. A high value on the Pauling scale indicates that an element has a strong ability to attract electrons in bonds. A low value indicates a weak ability.
When elements are placed in the periodic table, there is a general trend to their electronegativities. As you move left to right or bottom to top, the electronegativity of the element increases. The elements boron, nitrogen, sulfur, and germanium are all much, much closer to the top right of the periodic table. So, we’d expect their electronegativities to be much higher than that of strontium. So out of these five elements, our choice for the one with the lowest electronegativity is strontium.
Indeed, you can look up electronegativity values for each element. And, you’ll see that on the Pauling scale, strontium has a value of 0.95. If you look at the other five elements, you’ll see their electronegativities are much, much greater, at least two and for nitrogen even 3.4. So, going from top to bottom, the most electronegative element is nitrogen followed by sulfur, followed by boron, followed by germanium, followed by strontium. So, we can be fully confident that our final answer is strontium.