An electron at rest is accelerated through a potential difference of 200 V. If the specific charge o — Atomic Structure Chemistry Question

💡 Solution & Explanation

Kinetic energy gained $K.E. = eV = \frac{1}{2}mv^2$. The speed $v = \sqrt{2 \times (e/m) \times V} = \sqrt{2 \times 1.76 \times 10^{11} \times 200} = \sqrt{7.04 \times 10^{13}} = \sqrt{70.4 \times 10^{12}} \approx 8.39 \times 10^6$ m/s. Therefore, correct answer is B.