According to de Broglie's hypothesis applied to Bohr's model, the circumference of the 4th Bohr orbi — Atomic Structure Chemistry Question

💡 Solution & Explanation

The condition for an electron standing wave in a Bohr orbit is $2\pi r = n\lambda$. For the 4th orbit, $n=4$, meaning the circumference ($2\pi r$) is exactly $4$ times the de Broglie wavelength.