Practice portal › Atoms › Bohr Model of the Hydrogen Atom

According to Bohr's atomic model, the relation between the principal quantum number (n) and the radius of the orbit (r) is ______.

Asked in GUJCET 2011 · Postulates, radius, speed and angular momentum

• (1) r∝ n²
• (2) r∝1/(n²)
• (3) r∝1/n
• (4) r∝ n

Step-by-step solution

Why the other options are wrong

• (2) 1/(n²) is how the size of the energy varies, |Eₙ|=(13.6)/(n²) eV; the radius goes the other way and grows with n.
• (3) 1/n is how the orbital speed varies, vₙ∝1/n, not the radius.
• (4) n is how the angular momentum varies, L=(nh)/(2π); the radius grows faster, as n².

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.