Correct Answer: 6.25 × 10^18
Subject: 2025
Explanation: <b>Key Fact</b><br>Charge on one electron $e = 1.6 × 10^{-19}\text{ C}$.<br>Number of electrons in $1\text{ C}$ ($n = Q/e$) = $1 / (1.6 × 10^{-19}) = 6.25 × 10^{18}$ electrons.<br><br><b>Additional Info</b><br>Topic: Electrostatics & Current Electricity.<br><br><b>Why the other options are wrong</b><br>Option A: Correct.<br>Options B, C, and D have incorrect powers of ten.<br><br><b>Exam Trick</b><br>$1 / 1.6 = 0.625$; moving decimal gives $6.25 × 10^{18}$.<br><br><b>Final Answer</b><br>Option A — 6.25 × 10^18.