Chemistry

Question Analysis
This question involves explaining the period trend of electronegativity for Period 3 elements. The main focus is on linking atomic structure changes across a period to electronegativity variation.

Key Concept Explanation
Across a period, electrons are added to the same valence shell, so the number of electron shells and shielding effect remain constant.
The nuclear charge (number of protons) increases, pulling the valence electrons closer to the nucleus and strengthening the attraction for bonding electrons—this increases electronegativity.

Step-by-Step Solution
1. Eliminate incorrect options:
A: False (electron shells do not increase across a period; shielding is constant).
C: False (valence electrons increase from 1 to 7 across Period 3).
D: False (atom...