Which of the following elements has the highest electronegativity value on the Pauling scale?

Introduction / Context:
Electronegativity is a key concept in chemistry that describes how strongly an atom attracts shared electrons in a chemical bond. It helps predict bond polarity, molecular polarity, and reactivity patterns across the periodic table. This question asks you to identify which of the listed elements has the highest electronegativity, which is an important fact for understanding the behavior of many compounds.

Given Data / Assumptions:

• Elements given: chlorine, fluorine, bromine, and helium.
• We consider the standard electronegativity scale, such as the Pauling scale.
• We assume typical values at standard conditions, not unusual environments.

Concept / Approach:
On the periodic table, electronegativity generally increases across a period from left to right and decreases down a group. Fluorine, located in period 2 and group 17 (the halogens), is known to have the highest electronegativity of all elements. Chlorine and bromine are also halogens but are located further down the group and thus have lower electronegativity than fluorine. Helium is a noble gas, and it does not form many covalent bonds, so it is not considered highly electronegative in the usual bonding sense.

Step-by-Step Solution:
Step 1: Recall that among all elements, fluorine is widely recognized as the most electronegative. Step 2: Compare positions of chlorine, fluorine, and bromine in group 17. Fluorine is at the top, chlorine in the middle, and bromine below chlorine. Step 3: Apply the trend that electronegativity decreases down a group, so fluorine > chlorine > bromine. Step 4: Note that helium is a noble gas with a filled valence shell and minimal tendency to attract shared electrons. Step 5: Select fluorine as the element with the highest electronegativity among the given options.

Verification / Alternative check:
Standard data tables list the Pauling electronegativity of fluorine as about 4, which is the maximum on that scale. Chlorine has a value around 3, bromine slightly less, and noble gases often do not have standard values because they rarely form covalent bonds. By recalling or checking this table in any chemistry reference, you confirm that fluorine stands at the top, reinforcing the selection of fluorine as the correct answer.

Why Other Options Are Wrong:
Option A, chlorine, is quite electronegative but is still less electronegative than fluorine. Option C, bromine, lies further down the group than chlorine and therefore has an even lower electronegativity. Option D, helium, is a noble gas with a very stable electronic configuration and does not actively attract shared electrons in typical chemical bonds. None of these alternatives reach the electronegativity value of fluorine, so they cannot be correct.

Common Pitfalls:
A frequent mistake is to think that noble gases must be the most electronegative because they are very stable; however, stability is due to a filled valence shell and not due to attraction for extra electrons in a bond. Another common confusion is between chlorine and fluorine, since both are halogens used in real life, such as in disinfectants and toothpaste. Remembering the periodic trend that electronegativity is highest at the top right (excluding noble gases) helps avoid these errors and quickly points to fluorine.

Final Answer:
The element with the highest electronegativity among the options is fluorine.