The ratio of the velocity of an electron in the 1st Bohr orbit of a hydrogen atom to that in the 3rd — Atomic Structure Chemistry Question

💡 Solution & Explanation

Velocity $v \propto Z/n$. For H ($Z=1, n=1$), $v_1 \propto 1/1 = 1$. For $Be^{3+}$ ($Z=4, n=3$), $v_2 \propto 4/3$. Ratio $v_1 : v_2 = 1 : 4/3 = 3 : 4$.