Question

Which group contains the most electronegative elements in the periodic table?

• A. Group 1
• B. Group 2
• C. Group 16
• D. Group 17

Hint:

Recall how electronegativity changes as you move across a period from left to right, and down a group from top to bottom. Compare the four given groups using both trends together to find which one sits at the extreme end of both.

Answer 1

The Correct Option is D

Concept: Electronegativity is the tendency of an atom to attract shared electrons in a chemical bond. Across a period, electronegativity increases from left to right, while down a group it generally decreases.

Step 1: Observe the trend across the periodic table. Elements on the right side of the periodic table have higher electronegativity.

Step 2: Identify the group with the highest values. Group 17 elements (halogens) such as fluorine, chlorine, bromine, and iodine have very high electronegativities.

Step 3: Note the most electronegative element. Fluorine, which belongs to Group 17, is the most electronegative element in the periodic table.

Answer 2

Concept:

• Electronegativity depends mainly on two atomic properties: a small atomic radius and a strong effective nuclear charge pulling on the shared electron pair.
• Comparing the four given groups on these two properties directly, instead of only quoting the general trend, shows which one must have the highest electronegativity.

Step 1: Check Group 1, the alkali metals.
These atoms have large radii and only 1 electron in the outer shell, which they tend to lose rather than attract more electrons, so their electronegativity is among the lowest.

Step 2: Check Group 2, the alkaline earth metals.
These atoms are smaller than Group 1 atoms of the same period but still readily lose 2 electrons to form stable cations, keeping their electronegativity low.

Step 3: Compare Group 16 with Group 17 in the same period.
Both groups have a small atomic radius, but Group 17 atoms carry one more proton than Group 16 atoms of the same period, giving Group 17 atoms a stronger effective nuclear charge and a smaller radius still.

Step 4: Combine both effects for Group 17.
The smallest radius combined with the strongest pull on shared electrons among all these groups means Group 17 atoms attract a shared electron pair most strongly.

Final Answer: Group 17