The concept that contradicts the Bohr Model of an atom is: 

Which of the following ions has the same radius as the first Bohr orbit of the hydrogen atom?

1. ${\mathrm{He}}^{+},$ $n=2$

2. ${\mathrm{Li}}^{2+},n=2$

3. ${\mathrm{Be}}^{3+},$ $n=2$

4. ${\mathrm{Li}}^{2+},\mathrm{n}=3$

If the size of the first orbit of the hydrogen atom is 5.29 nm, the size of the second orbit of He⁺ is

1. 2.65 nm

2. 21.16 nm

3. 10.58 nm

4. 5.29 nm