The speed of the electron in the $n=2$ orbit of $\mathrm{B}{}^{4+}$ is how many times the speed of the electron in the first orbit of hydrogen?

More questions on Bohr model: energy, radius, velocity, ionisation energy

• The speed of the electron in the second Bohr orbit of hydrogen, compared with its speed in the first orbit, is NEET level
• Take E_1 = -13.6 eV for hydrogen. The energy of an electron in the n=2 level of Li^2+ is JEE Main level
• Use a_0 = 0.529 AA. The radius of the third Bohr orbit of He+ is JEE Main level
• Using E_1 = -13.6 eV, the minimum energy needed to excite a ground-state hydrogen atom to the n=3 level is JEE Main level
• Take E_1=-13.6 eV for hydrogen. In the n=2 level of Be^3+, the potential energy of the electron is JEE Main level
• Use a_0 = 52.9 pm. Calculate the radius of the fourth Bohr orbit of Li^2+ in pm (nearest integer). JEE Main level