The element with the highest electronegativity is fluorine.
According to the provided reference, fluorine possesses the highest electronegativity (EN = 4.0) among the main group elements. This signifies its strong tendency to attract electrons from other elements with lower electronegativities. Cesium, in contrast, has the lowest electronegativity (EN = 0.79).
Here's a table summarizing the electronegativity of fluorine and cesium:
| Element | Electronegativity (EN) |
|---|---|
| Fluorine (F) | 4.0 |
| Cesium (Cs) | 0.79 |
Therefore, fluorine's high electronegativity makes it highly reactive, readily forming compounds with other elements by gaining electrons.
