Final answer:
Halogens are the group with the largest electronegativity. This group includes elements like fluorine, which has the highest electronegativity of all elements. Alkali metals and alkaline earth metals have lower electronegativities, and noble gases generally do not have assigned electronegativities. Option a.
Step-by-step explanation:
A chemist looking to use an element with a large electronegativity should consider elements from the halogens group. In the periodic table, electronegativity increases from left to right across a period due to an increase in nuclear charge. Likewise, electronegativity generally decreases from top to bottom within a group because of larger atomic size. Option a.
Among the options listed, halogens have the highest electronegativities, with fluorine being the most electronegative element of all. Alkaline earth metals, alkali metals, and noble gases have lower electronegativities, with alkali metals having the lowest. Since noble gases generally do not form compounds under normal conditions, they are typically excluded when considering electronegativities.
Therefore, the correct group that has the largest electronegativity is the halogens.