Is the atomic radii of nitrogen larger than oxygen or smaller?
The atomic radii of nitrogen is larger than oxygen.
Oxygen: 60 PPM
Nitrogen: 65 PPM
The greater the value of PPM, the bigger the atomic radii.
Atomic radii decreases as you go across a period due to the increase of electrons and protons. As protons is more stronger than electrons and weight 2000 times as much, they are going to attract the outer electrons more towards the nucleus. Atomic radius is the distance between the centre of nucleus to the furthest electron on the last shell, if the nucleus (protons+neutrons) attract these electrons greater towards the nucleus, this atomic radii decrease. That's why you find a decrease in atomic radius across a period.
More information here: https://sciencing.com/affects-atomic-radius-23091.html