Pits are reinitiated when they are ______.

• A. Drying
• B. Cooling
• C. Rewetted
• D. Oxidizing

Answer: (C)

Pits reinitiate when they are rewetted because the reintroduction of liquid fills the pit with conductive electrolyte again, replenishing aggressive ions (like chlorides) and restoring the conditions needed for localized anodic dissolution. While the surface may have been passive or the pit temporarily inactive during drying, rewetting lowers the impedance and brings in oxygen and ions that promote renewed attack at the pit mouth, restarting pit growth. Drying reduces ion transport and reaction rates, cooling slows kinetics, and oxidation tends to promote surface passivation instead of starting new pits, so they don’t reinitiate in those conditions.