Question

which of the following has the greatest electronegativity? o n cs he

Explanation:

Step1: Recall electronegativity trend

Electronegativity increases across a period and decreases down a group in the periodic - table.

Step2: Analyze the given elements

Oxygen (O) is in Group 16 and Period 2. Nitrogen (N) is in Group 15 and Period 2. Cesium (Cs) is in Group 1 and Period 6. Helium (He) is a noble gas in Group 18 and Period 1. Noble gases generally do not have well - defined electronegativities in the same sense as other elements. Among O and N, oxygen is more electronegative as it is further to the right in the same period. Cs is a very electropositive metal with low electronegativity.

Answer:

O