Which of the following elements has the lowest electronegativity value?

• A. Fluorine (F)
• B. Oxygen (O)
• C. Francium (Fr)
• D. Cesium (Cs)

Answer: (C)

Verified step by step guidance

1. Understand that electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond.
2. Recall the general trend of electronegativity on the periodic table: it increases across a period (left to right) and decreases down a group (top to bottom).
3. Identify the positions of the given elements on the periodic table: Fluorine (F) and Oxygen (O) are in the upper right, while Cesium (Cs) and Francium (Fr) are in the lower left.
4. Since electronegativity decreases down a group, elements like Francium (Fr) and Cesium (Cs) have lower electronegativity values compared to Fluorine and Oxygen.
5. Between Francium and Cesium, Francium is located further down the group, so it has the lowest electronegativity value among the options.