engineering physics MCQ #534

engineering physics MCQ #534

1. Question 1

   Q1. The radius of the first orbit of hydrogen atom is 0.053 nm. What is the radius of the first orbit of He+?

   • A) 0.0265 nm
   • B) 0.053 nm
   • C) 0.106 nm
   • D) 0.212 nm

   Answer: 0.0265 nm

   Explanation: Radius is inversely proportional to Z. For He+, Z = 2, so radius = 0.053 / 2 = 0.0265 nm.