Question

The period and group numbers of the element having maximum electronegativity in the long form of periodic table, respectively, are

• A. \(2, 17 \)
• B. \(3, 17 \)
• C. \(1, 18 \)
• D. \(2, 16 \)

Hint:

To quickly find the most electronegative element: General Trend:} Electronegativity increases up a group and to the right across a period. Exclusion:} Noble gases (Group 18) are generally not considered in typical electronegativity comparisons due to their inert nature. Key Element:} Fluorine (F) is the most electronegative element on the periodic table. Locating Fluorine:} Period 2, Group 17 (Halogens).

Answer 1

The Correct Option is A

Step 1: Understand the trend of electronegativity in the periodic table.
Electronegativity is a chemical property that describes the tendency of an atom to attract electrons towards itself in a chemical bond. Across a Period (left to right): Electronegativity generally increases. This is because as you move from left to right, the nuclear charge (number of protons) increases, and the atomic radius decreases (due to increased effective nuclear charge). This stronger attraction of the nucleus for valence electrons leads to higher electronegativity. Down a Group (top to bottom): Electronegativity generally decreases. As you move down a group, the number of electron shells increases, leading to a larger atomic radius and increased shielding of the valence electrons from the nucleus. This reduces the attraction of the nucleus for valence electrons, resulting in lower electronegativity. 
Step 2: Identify the element with maximum electronegativity.
Based on these trends, the element with the highest electronegativity should be located in the upper-right corner of the periodic table.
The noble gases (Group 18) are generally excluded from electronegativity discussions because they have complete valence shells and rarely form chemical bonds.
Among all the elements that actively form bonds, Fluorine (F) is universally recognized as the element with the highest electronegativity (its Pauling electronegativity value is 3.98). 
Step 3: Determine the period and group numbers of Fluorine.
Fluorine (F) has an atomic number of 9.
Its electron configuration is \(1s^2 2s^2 2p^5\).
Period Number: The period number corresponds to the highest principal quantum number (\(n\)) in the electron configuration. For Fluorine, the highest \(n\) is 2. So, Fluorine is in Period 2.
Group Number: For p-block elements, the group number is 10 plus the number of valence electrons. Fluorine has 2 electrons in the 2s subshell and 5 electrons in the 2p subshell, totaling 7 valence electrons (\(2s^2 2p^5\)).
So, the Group Number = 10 + 7 = 17. Fluorine belongs to Group 17 (the Halogens). 
Step 4: State the final answer.
The element having maximum electronegativity is Fluorine, which is in Period 2 and Group 17. The final answer is $\boxed{2, 17}$.