The correct pattern in electronegativity that elements in the periodic table display is:
Electronegativity increases from left to right across a period and decreases down a group.
Specifically, electronegativity is generally lowest in the bottom left corner of the periodic table (where alkali metals and heavier metals are found) and increases to the top right corner (where halogens and noble gases are located, though noble gases typically do not form bonds).
So, to clarify your statements:
- "Electronegativity is lowest on the left and right sides of the periodic table, and highest in the middle of a row" is incorrect.
- "Electronegativity is highest on the left and right sides of the periodic table, and lowest in the middle of a row" is incorrect.
- "Electronegativity decreases from left to right within a row of the periodic table" is incorrect.
In summary, electronegativity increases across a row (from left to right) and decreases down a group (from top to bottom).