Which of the following elements has the highest electronegativity?

• A. helium
• B. fluorine
• C. bromine
• D. chlorine

Answer: (B)

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 in the periodic table: it increases from left to right across a period and decreases from top to bottom within a group.
3. Identify the positions of the given elements in the periodic table: helium is a noble gas in period 1, fluorine and chlorine are halogens in period 2 and 3 respectively, and bromine is a halogen in period 4.
4. Compare the electronegativities of the halogens (fluorine, chlorine, bromine) since noble gases like helium typically do not have defined electronegativity values due to their inertness.
5. Conclude that fluorine, being the most electronegative element in the periodic table and located at the top of the halogen group, has the highest electronegativity among the options.